Degradation Mechanism of Plant Fiber and Application of Synergistic Fermentation of Bacteria and Enzymes

YI Lanlan; ZHU Junhong; CHENG Wenjie; ZHAO Sumei

doi:10.12418/CJAN2024.121

Chinese Journal of Animal Nutrition >

2024 , Vol. 36 >Issue 3: 1361 - 1374

DOI: https://doi.org/10.12418/CJAN2024.121

REVIEW

Degradation Mechanism of Plant Fiber and Application of Synergistic Fermentation of Bacteria and Enzymes

YI Lanlan ,
ZHU Junhong ,
CHENG Wenjie ,
ZHAO Sumei ^,^*

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College of Animal Science and Technology, Yunnan Agricultural University, Kunming 650201, China

*professor, E-mail: zhaosm2009@126.com

Received date: 2023-09-14

Online published: 2024-03-13

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Abstract

The synergistic fermentation of bacteria and enzymes can increase the degradation efficiency of fiber and anti-nutritional factors in feed ingredients, improve fermentation quality and palatability, and play a positive role in the growth and intestinal health of livestock and poultry. This review introduced the degradation mechanism of plant fiber and the types of fiber-degrading enzymes produced by fungi and bacteria, and summarized the application effects of synergistic fermented feeds of bacteria and enzymes in animal production, in order to provide reference for further exploring the synergistic fermentation mechanism of bacteria and enzymes.

Key words： synergy of bacteria and enzymes; Lactobacillus; Bacillus; lignin peroxidase; cellulase; xylanase

Cite this article

YI Lanlan , ZHU Junhong , CHENG Wenjie , ZHAO Sumei . Degradation Mechanism of Plant Fiber and Application of Synergistic Fermentation of Bacteria and Enzymes[J]. Chinese Journal of Animal Nutrition, 2024 , 36(3) : 1361 -1374 . DOI: 10.12418/CJAN2024.121

微生物是饲料原料发酵的主要驱动力,但单纯的微生物发酵对饲料原料中纤维物质或抗营养因子的降解有限,在此基础上添加纤维素酶、植酸酶或蛋白酶等能有效降解纤维物质和抗营养因子,提高饲料原料营养价值^[1]。外源性酶与微生物间的协同作用主要涉及纤维素酶和木聚糖酶,它们分别降解纤维素和半纤维素。纤维素酶由至少三大类酶组成,即内切葡聚糖酶、外切葡聚糖酶和β-葡萄糖苷酶,同时木聚糖酶在半纤维素的降解中发挥作用,与纤维素酶协同降解纤维素^[2]。微生物在发酵过程中能产生少量的酶,可构建发酵环境,提升发酵物品质,且部分益生菌进入畜禽消化道后仍发挥益生作用。Du等^[3]报道,菌酶协同发酵桑叶改善桑叶青贮饲料的微生物群落结构、发酵品质,有效抑制有害微生物的生长,主导厌氧发酵过程,其作用机理是乳酸菌作为桑叶青贮过程的优势菌种,能通过糖酵解途径将葡聚糖酶、果胶酶和羧甲基纤维素酶分解纤维素和半纤维素产生的糖转化为乳酸。全株玉米接种枯草芽孢杆菌青贮,可降低粗纤维含量,增加粗蛋白质含量,提升全株玉米的营养价值^[4],且枯草芽孢杆菌进入反刍动物消化道仍发挥益生作用。因此,菌酶协同发酵是实现饲料原料高值化利用的重要途径。

1 植物纤维的降解机制

植物纤维主要由纤维素、半纤维素和木质素组成。纤维素仅含通过氢键网络连接的晶体结构的葡萄糖链,半纤维素具有木糖链主链和各种乙酰化糖单元的侧链,木质素是由苯丙烷单体组成的复杂聚合物^[5]。纤维素的生物降解涉及纤维素酶(内切葡聚糖酶)、纤维二糖水解酶(外切葡聚糖酶)和β-葡萄糖苷酶的协同作用^[6]。内切葡聚糖酶切割纤维素链的无定形区域,使纤维二糖水解酶在链末端发挥作用。纤维二糖水解酶、内切葡聚糖酶和纤维素酶水解纤维素有“两步”过程,首先在几分钟内纤维长度减少,然后在60~90 min内无定形纤维素溶解(占初始纤维素的约2%),此外,膨胀素也能通过无定形纤维素来促进纤维断裂^[7]。纤维素酶优先水解低序纤维素,纤维长度减少、发生膨胀并产生断裂^[8]。纤维素酶作用于纤维素底物,是天然结晶纤维素完全酶促水解的关键。最后,β-葡萄糖苷酶将纤维二糖水解为葡萄糖。

结晶纤维素和其他顽固多糖(如几丁质)可被细菌和真菌中发现的溶解多糖单加氧酶降解^[9]。里氏木霉生产的纤维素酶7B对纤维素的初始水解和溶胀的联合作用暴露了单个微纤维和微纤维束,导致纤维结构松散并在纤维表面暴露出微纤维^[10]。半纤维素水解是内切酶(在内部裂解主链)、外切酶(释放单糖)以及相关酶(切割聚合物或寡糖侧链以最终释放单糖或二糖)协同作用的结果。此外,玉米中葡萄糖醛阿拉伯木聚糖的不溶性和高苯酚含量使木聚糖酶降解效率降低,体内和体外研究均表明脱支酶(阿拉伯呋喃糖苷酶、α-葡萄糖醛酸酶和酯酶等)能通过破坏酚键显著增加纤维的降解率^[11]。微生物分泌的纤维降解酶将纤维素降解为畜禽可利用的单糖或寡糖。

2 菌酶协同发酵中的菌及其生产的酶

2.1 真菌生产的纤维降解酶

微生物在木质素的降解过程中产生多种水解酶,包括木质素过氧化物酶、纤维素酶、木聚糖酶、漆酶等^[12]。木质素是一种芳香族聚合物,由愈创木基、紫丁香基和对羟基苯基3种亚基组成。黄孢原毛平革菌是白腐真菌的一种,其产生的木质素过氧化物酶于1982年被发现^[13]。使用黄孢原毛平革菌、变色栓菌和平菇降解玉米秸秆能提高纤维素、半纤维素和木质素的降解率^[14]。白腐真菌具有强大的木质素降解酶系统,能通过分泌漆酶、锰过氧化物酶、木质素过氧化物酶等木质素分解酶参与降解木质素^[15]。漆酶属于多铜氧化酶家族,包括抗坏血酸氧化酶、氧化铁酶、亚硝酸还原酶和铜蓝蛋白等,其是由许多具有不同底物特异性和不同生物功能的蛋白质组成的酶,铜氧还蛋白样结构域使所有多铜氧化酶能将氧气还原为水,而不产生有害的副产物^[16]。除白腐真菌能降解木质素外,部分细菌如红球菌、恶臭假单胞菌、芽孢杆菌、新鞘氨醇菌和弗氏柠檬酸杆菌也表现出木质素降解能力^[17]。

真菌已被广泛用于生产纤维降解酶^[18],具体见表1。里氏木霉常用于工业化生产纤维素酶和半纤维素酶^[19]。有研究表明,里氏木霉细胞内糖转运蛋白利用乳糖协助其生产纤维素酶^[20]。斜卧青霉以纤维素、脱淀粉麦麸和稻草为碳源能生产阿魏酸酯酶和纤维素酶^[21]。在自然界广泛存在的酵母菌是子囊菌门真菌,具有降解纤维素和木聚糖的酶活性^[22]。褐腐真菌能生物降解木材,降低其半纤维素和纤维素的含量和纤维素的结晶度^[23]。

表1 真菌生产的纤维降解酶

Table 1 Fiber-degrading enzymes produced by fungi

真菌种类 Fungal species	底物 Substrate	产生的酶 Produced enzyme	参考文献 References
斜卧青霉Penicillium decumbens	纤维素、脱淀粉麦麸和稻草	阿魏酸酯酶、纤维素酶	[21]
黑曲霉Aspergillus niger	玉米秸秆	木聚糖酶	[24]
酿酒酵母MK-157 Saccharomyces cerevisiae MK-157	玉米芯	木聚糖酶	[26]
酿酒酵母SCPW17 Saccharomyces cerevisiae SCPW17	玉米芯	纤维素酶、木聚糖酶、木质素酶	[27]
黑曲霉F12 Aspergillus niger F12	咖啡渣和麦麸	β-甘露聚糖酶、β-糖苷酶	[28]

真菌处理玉米秸秆常用于工业生产半纤维素酶,黑曲霉、巨大芽孢杆菌和酵母菌是主要用于生产木聚糖酶的菌种,木聚糖酶是分解半纤维素的主要酶类。黑曲霉和巨大芽孢杆菌分别接种于碱处理玉米秸秆,黑曲霉和巨大芽孢杆菌产生的木聚糖酶在40 ℃培养30和45 min后分别达到最高的活性(3.67和3.36 U/mL);pH 5.0时黑曲霉产生的木聚糖酶最高活性达4.58 U/mL,pH 6.2时巨大芽孢杆菌产生的木聚糖酶最高活性达3.58 U/mL^[24]。巴斯德毕赤酵母产生的木聚糖酶在最适条件下活性达442.53 U/mL^[25]。酿酒酵母MK-157在Sabouraud葡萄糖肉汤中30 ℃下培养48 h,将酵母细胞固定在碱处理玉米芯基质上,将固定化基质转移到含有1%木聚糖的矿物盐培养基中,并在30 ℃下孵育24 h,可生产木聚糖酶^[26]。酿酒酵母SCPW17能发酵玉米芯生产纤维素酶、木聚糖酶和木质素酶,活性分别为17.63 U/gds、29.35 U/gds和150.75 μmol/min^[27]。此外,使用黑曲霉F12发酵咖啡渣和麦麸的混合物组,120 h后β-甘露聚糖酶和β-糖苷酶的产量分别为51.97和72.54 U/g^[28]。

2.2 细菌生产的纤维降解酶

将地球微生物组计划发布的序列与测序的原核基因组之间进行大规模比对,Li等^[29]认为几乎所有原核生物群落都具有降解纤维素、木聚糖和几丁质的功能潜力。部分细菌利用不同底物生产的纤维素降解酶的种类见表2。原小单孢菌属VP111处理麦秆和甘蔗渣产生纤维素酶、木聚糖酶和果胶酶,其中纤维素酶水解多种纤维素底物,包括羧甲基纤维素钠、Whatman 1号滤纸、微晶纤维素、对硝基苯基-β-D-吡喃葡萄糖苷、昆布多糖和纤维素粉^[30]。枯草芽孢杆菌亚种JJBS250以甘蔗渣为底物固态发酵生产木聚糖酶,产量为20.35 U/g底物^[31]。嗜热地芽孢杆菌GS90在pH为8和温度为55 ℃条件下生产的木聚糖酶比活性最佳为1 671.4 U/mg^[32]。高地芽孢杆菌RS3025利用碱处理的稻草废弃物生产木聚糖酶,72 h获得最大木聚糖酶活性(2 518.51 U/mL)^[33]。芽孢杆菌属以麦麸为唯一发酵底物,144 h生产木聚糖酶2 943 U/g^[34]。沙福芽孢杆菌M35和高地芽孢杆菌J208发酵柑橘皮和麦麸的混合底物,可同时生产木聚糖酶和果胶酶^[35]。

表2 细菌生产的纤维降解酶

Table 2 Fiber-degrading enzymes produced by bacteria

细菌种类 Bacterial species	底物 Substrate	产生的酶 Produced enzyme	参考文献 References
原小单孢菌属VP111 Promicromonospora sp. VP111	麦秆和甘蔗渣	纤维素酶、木聚糖酶和果胶酶	[30]
枯草芽孢杆菌亚种JJBS250 Bacillus subtilis subsp. Subtilis JJBS250	甘蔗渣	木聚糖酶	[31]
高地芽孢杆菌RS3025 Bacillus altitudinis RS3025	稻草废弃物	木聚糖酶	[33]
芽孢杆菌属Bacillus	麦麸	木聚糖酶	[34]
沙福芽孢杆菌M35和高地芽孢杆菌J208 Bacillus safensis M35 and Bacillus altitudinis J208	柑橘皮和麦麸	木聚糖酶和果胶酶	[35]
枯草芽孢杆菌Bacillus subtilis	沉香粉	纤维素酶	[36]
芽孢杆菌PM06 Bacillus sp. PM06	淀粉和羧甲基纤维素	α-淀粉酶、纤维素酶	[40]
地衣芽孢杆菌HDYM-04 Bacillus licheniformis HDYM-04	葡萄糖或魔芋粉	β-甘露聚糖酶	[42]
枯草芽孢杆菌US191 Bacillus subtilis US191	刺槐豆胶、咖啡渣粉、枣子粉和仙人掌果粉	β-甘露聚糖酶	[43]
Thermobacillus xylanilyticus	麦麸和麦秆	木聚糖酶、乙酰酯酶和 β-木糖苷酶	[44]

枯草芽孢杆菌能降解沉香粉的纤维素,纤维素酶活性高达0.22 U/mL,并且对花椒和黄檀具有类似作用^[36]。在玉米秸秆中添加枯草芽孢杆菌、地衣芽孢杆菌、蜡样芽孢杆菌和链霉菌形成共降解系统,可促进子囊菌门产生更多腐殖质前体,提高纤维素分解效率^[37]。假单胞菌属、黄杆菌属、固氮螺菌属、毛球菌属、不动杆菌属和短波单胞菌属降解秸秆14 d后,滤纸酶和内切葡聚糖酶的活性分别为2.55和2.34 U/mL;28 d后,木聚糖酶、漆酶和木质素过氧化物酶活性分别为9.86、132.16和85.43 U/mL;高通量测序结果发现变形菌门、厚壁菌门和拟杆菌门是秸秆不同降解阶段的主要菌门^[38]。地芽孢杆菌属除具有高纤维素酶活性外,还具有良好的木聚糖酶、纤维二糖酶和淀粉酶活性,适用于生产各种生物技术和工业应用的酶^[39]。芽孢杆菌PM06能在淀粉和羧甲基纤维素作为唯一碳源的培养基中生长,α-淀粉酶和纤维素酶在48 h时获得最大产量^[40]。

甘露聚糖是半纤维素的主要成分,广泛存在于植物组织中,β-甘露聚糖酶是主要的甘露聚糖降解酶,可由不同的植物、动物、放线菌、真菌和细菌产生^[41]。地衣芽孢杆菌HDYM-04以葡萄糖或魔芋粉为碳源时,24 h β-甘露聚糖酶活性分别为288.13和696.35 U/mL^[42]。枯草芽孢杆菌US191在0.25 g/L刺槐豆胶、5 g/L咖啡渣粉、5 g/L枣子粉和5 g/L仙人掌果粉的条件下发酵生产β-甘露聚糖酶,产量为8.75 U/mL^[43]。Thermobacillus xylanilyticus是一种嗜热半纤维素分解细菌,可用于生产热稳定性半纤维素酶,可使用麦麸和麦秆作为碳源生产半纤维素酶^[44]。

木质素的降解率影响纤维素和半纤维素的降解率。木质素在堆肥处理中难以降解,进而影响纤维素和半纤维素的降解。堆肥处理的半纤维素、纤维素和木质素的降解率分别为19.9%、14.7%和12.5%,添加混合微生物处理后降解率分别提高至44.4%、34.9%和39.2%^[45]。漆酶、木质素过氧化物酶和锰过氧化物酶处理玉米秸秆的试验发现漆酶是混合酶反应的起始酶,3种酶协同破坏木质素的关键结构并打开苯环,产生更多酸性化合物,木质素降解率达25.79%^[46]。枯草芽孢杆菌和地衣芽孢杆菌都能分泌漆酶,漆酶降解木质素的能力已被充分证明^[47]。解淀粉芽孢杆菌发酵降解秸秆15 d后木质素降解率为28.55%,与真菌达到的降解率接近^[48]。因此,提高木质素的降解率是提高可溶性糖含量的有效途径。

2.3 其他酶

饲料中常使用植酸酶、脂肪酶、蛋白酶等提升其营养价值。植酸酶是饲料中的常用酶,能改善单胃动物生长性能。枯草芽孢杆菌JJBS250在30 ℃、pH 5.0的条件下发酵麦麸48 h后,分泌出高植酸酶滴度^[49]。嗜热真菌发酵米糠,添加0.5%硫酸铵为氮源,在45 ℃下培养9 d,植酸酶、内切葡聚糖酶和木聚糖酶产量分别为58、12和48 U/g底物^[50]。微生物脂肪酶催化长链脂肪酸的水解,芽孢杆菌属、无色杆菌属、产碱菌属、节杆菌属、假单胞菌属和属于真菌的青霉属、镰刀菌属、曲霉属能用于生产脂肪酶^[51]。乳酸菌能将糖发酵为乳酸并产生蛋白水解酶,蛋白水解酶在细菌细胞内合成,大部分分泌到细胞外,其主要功能是将蛋白质水解为细菌能吸收的成分^[52]。果胶酶是水解果胶的混合酶,主要存在于微生物和高等植物中,已能利用微生物尤其是真菌进行商业化制备^[53]。淀粉酶可将淀粉水解成糊精和更小的葡萄糖单元聚合物,热稳定淀粉酶占淀粉酶市场的近25%^[54]。

3 菌酶协同发酵的饲料原料

3.1 高纤维饲料原料

菌酶协同发酵饲料主要分为2种类型:一是单独发酵某种饲料原料后配制饲粮;二是配制全价饲料后添加菌酶进行发酵。根据饲料原料的营养特性使用不同的菌酶组合处理,其目的主要是降解纤维素和消除抗营养因子,菌酶协同发酵高纤维饲料原料的效果见表3。高纤维饲料原料以玉米秸秆为代表,全球玉米秸秆年产量约10亿t,主要被焚烧、掩埋和堆肥,难以形成经济效益。玉米秸秆主要可分为纤维皮和纤维芯两部分,纤维皮由纤维素和木质素组成,纤维芯主要包含半纤维素和少量木质素^[55-56]。利用黄孢原毛平革菌、纤维素酶和木聚糖酶青贮玉米秸秆19 d后,其中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和酸性洗涤木质素(ADL)含量比未添加菌酶青贮玉米秸秆分别降低23.4%、20.13%和7.68%^[57]。甜高粱与植物乳杆菌、纤维素酶和木聚糖酶青贮21 d,pH降至4.2以下,乳酸/乙酸>2.0,乳酸/总有机酸>0.65,实现甜高粱青贮效果优化^[58]。在全株玉米和花生蔓中添加植物乳杆菌和纤维素酶,可使pH、ADF和NDF含量降低,乳酸含量增加,乳酸杆菌、克雷伯氏菌、沙雷氏菌和魏斯氏菌为主要微生物^[59]。使用黑曲霉、嗜酸乳杆菌、布氏乳杆菌、产朊假丝酵母、纤维素酶和木聚糖酶室温密封发酵香菇菌糠30 d能改善其营养价值,使NDF、ADF、ADL、钙和磷含量下降,粗蛋白质和粗脂肪含量提高^[60]。使用酿酒酵母、黑曲霉、枯草芽孢杆菌和植酸酶在30 ℃恒温培养箱中发酵辣木茎秆粉7 d,可提高其乳酸和蛋白质含量,降低NDF、ADF和植酸含量^[61]。在苜蓿和羊草中添加植物乳杆菌和纤维素酶混合室温青贮1~30 d,pH随青贮时间的增加而降低,30 d时NDF含量、微生物Shannon指数和Simpson指数降低,乳酸菌的相对丰度增加,乳酸和乙酸的浓度提高^[62]。桑叶中添加干酪乳杆菌和纤维素酶混合青贮,28 ℃发酵30 d,乳酸、真蛋白质和总黄酮含量提高,抗氧化活性和微生物蛋白产量增加,pH、氨态氮和纤维含量较低^[63]。

表3 菌酶协同发酵高纤维饲料原料的效果

Table 3 Effects of synergistic fermentation of bacteria and enzyme on high fiber feed materials

底物 Substrates	菌酶组合 Combination of bacteria and enzymes	效果 Effects	参考文献 References
玉米秸秆 Corn stalk	黄孢原毛平革菌、纤维素酶、木聚糖酶	NDF、ADF、ADL含量降低	[57]
甜高粱 Sweet sorghum	植物乳杆菌、纤维素酶、木聚糖酶	pH降至4.2以下,乳酸/乙酸> 2.0,乳酸/总有机酸>0.65	[58]
全株玉米和花生蔓 Whole-plant corn and peanut vine	植物乳杆菌、纤维素酶	pH、ADF和NDF含量降低,乳酸含量增加	[59]
香菇菌糠 Spent mushroom substrate	黑曲霉、嗜酸乳杆菌、布氏乳杆菌、产朊假丝酵母、纤维素酶、木聚糖酶	NDF、ADF、ADL、钙和磷含量下降, 粗蛋白质和粗脂肪含量增加	[60]
辣木茎秆粉 Moringa stem powder	酿酒酵母、黑曲霉、枯草芽孢杆菌、植酸酶	NDF、ADF和植酸含量降低,乳酸和粗蛋白质含量增加	[61]
苜蓿和羊草 Alfalfa and Leymus chinensis	植物乳杆菌、纤维素酶	NDF含量降低,粗蛋白质含量升高	[62]
桑叶Mulberry leaves	干酪乳杆菌、纤维素酶	NDF、ADF含量降低,总黄酮含量增加	[63]

NDF:中性洗涤纤维 neutral detergent fiber;ADF:酸性洗涤纤维 acid detergent fiber;ADL:酸性洗涤木质素 acid detergent lignin。下表同 the same as below。

3.2 高蛋白质饲料原料

我国畜禽养殖中主要使用玉米-豆粕型饲粮,但豆粕含有抗营养因子如大豆球蛋白、β-伴大豆球蛋白、胰蛋白抑制剂和植酸,损害动物肠道健康,降低生产性能^[64]。菌酶协同发酵可消除蛋白质饲料原料中的抗营养因子,其对高蛋白质饲料原料的效果见表4。使用枯草芽孢杆菌和碱性蛋白酶30 ℃发酵豆粕72 h,β-伴大豆球蛋白消除率为75.27%,氨基酸含量提高3.96倍,并能提高乳酸、柠檬酸、乙酸等有机酸的含量,显著改善豆粕的营养价值和适口性^[65]。使用酿酒酵母、枯草芽孢杆菌、干酪乳杆菌和蛋白酶发酵豆粕,37 ℃发酵72 h,水苏糖、棉籽糖、大豆球蛋白、β-伴大豆球蛋白、胰蛋白酶抑制因子等抗营养因子消除率增加^[66]。花生粕存在抗营养因子、过敏蛋白和黄曲霉毒素等^[67]。使用短乳杆菌、纤维素酶、植酸酶和酸性蛋白酶发酵处理花生粕48 h,粗蛋白质含量由46.4%提高至50.6%,总酸含量由0.6%提高至4.7%,且抗氧化性明显增强^[68]。

表4 菌酶协同发酵高蛋白质饲料原料的效果

Table 4 Effects of synergistic fermentation of bacteria and enzymes on high protein feed materials

底物 Substrates	菌酶组合 Combination of bacteria and enzymes	效果 Effects	参考文献 References
豆粕 Soybean meal	枯草芽孢杆菌、碱性蛋白酶	β-伴大豆球蛋白降解率为 75.27%,氨基酸含量提高3.96倍	[65]
豆粕 Soybean meal	酿酒酵母、枯草芽孢杆菌、干酪乳杆菌、蛋白酶	大豆球蛋白消除率为69.93%,β-伴大豆球蛋白消除率为59.57%,胰蛋白酶抑制因子消除率为98.03%,尿素酶完全消除,水苏糖消除率为99.54%,棉籽糖消除率为83.24%	[66]
花生粕 Peanut meal	短乳杆菌、纤维素酶、植酸酶、酸性蛋白酶	粗蛋白质含量提高至50.6%, 总酸含量提高至4.7%	[68]
豆粕、玉米芯和麸皮 Soybean meal, corn cobs and bran	枯草芽孢杆菌、地衣芽孢杆菌、植物乳杆菌、酵母菌、纤维素酶、木聚糖酶、果胶酶、甘露聚糖酶	木聚糖含量提高至1.421 mg/g	[69]
豆粕、黄芪、绞股蓝和马齿苋 Soybean meal, Astragalus, Gynostemma pentaphyllum and Purslane	植物乳杆菌、枯草芽孢杆菌、纤维素酶、果胶酶	粗多糖含量为280.46 mg/g	[70]

菌酶协同发酵可提高豆粕与高纤维饲料原料混合后的多糖含量。豆粕、玉米芯和麸皮混合后加入枯草芽孢杆菌、地衣芽孢杆菌、植物乳杆菌、酵母菌、纤维素酶、木聚糖酶、果胶酶和甘露聚糖酶36 ℃发酵72 h,木聚糖含量达1.421 mg/g^[69]。豆粕、黄芪、绞股蓝和马齿苋混合后加入植物乳杆菌、枯草芽孢杆菌、纤维素酶和果胶酶,在料液比为1∶1.2(g/mL)、发酵温度35 ℃、发酵时间60 h、接种量12%的最适发酵工艺下,粗多糖含量为280.46 mg/g^[70]。

4 菌酶协同发酵饲料在畜禽生产中的应用

4.1 在猪生产中的应用

菌酶协同发酵饲料能有效降低仔猪腹泻率,提高仔猪和育肥猪的生长性能,对肠道菌群组成也具有积极作用,其在猪生产中的应用效果见表5。枯草芽孢杆菌、植物乳杆菌、纤维素酶、蛋白酶、甘露聚糖酶、α-淀粉酶和葡聚糖酶协同发酵复方中草药与玉米-豆粕型饲粮,第1步是37 ℃好氧发酵20 h,第2步是37 ℃厌氧发酵5 d,将得到的菌酶协同发酵饲料饲喂杜×长×大断奶仔猪28 d,可改善断奶仔猪的生长状况,减少腹泻,提高机体免疫和抗氧化功能^[71]。将植物乳杆菌、戊糖片球菌、黑曲霉、蛋白酶、淀粉酶、脂肪酶和纤维素酶发酵12 h的玉米-豆粕型饲粮饲喂杜×长×大猪21 d,可提高营养物质的消化率,改善仔猪的肠道健康,降低腹泻率,提高生长性能,且效果相当于或优于添加金霉素饲粮^[72]。在1 kg玉米芯混合料加入2.5%的复合益生菌(发酵乳杆菌、酿酒酵母和枯草芽孢杆菌)和0.06%~0.08%的非淀粉多糖酶协同发酵制备发酵饲料,发酵温度25~30 ℃,发酵时间5~7 d,使用发酵饲料替代饲粮中6%的玉米和豆粕,能显著增加杜×长×大猪的日采食量、日增重和养分消化率,降低料重比,增加肠道中乳酸菌等有益菌的相对丰度,显著减少肠道和粪便中大肠杆菌等致病菌的相对丰度,提高免疫能力,显著增加回肠黏膜中细胞因子含量和分泌型免疫球蛋白A(sIgA)、白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)基因表达水平,提高生长性能、屠宰性能和肉品质,改善其肠道微生态平衡和免疫力^[73]。芽孢杆菌、粪肠球菌和复合酶制剂厌氧发酵玉米-豆粕型饲粮48 h,可降解饲料中80%的大豆抗原蛋白,且乳酸含量达到122.18 mmol/kg,替代10%基础饲粮后饲喂杜×长×大仔猪24 d,采食量和平均日增重提高^[74]。

表5 菌酶协同发酵饲料在猪生产中的应用效果

Table 5 Application effects of synergistic fermented feeds of bacteria and enzymes in pig production

底物 Substrates	菌酶组合 Combination of bacteria and enzymes	品种 Breeds	效果 Effects	参考文献 References
复方中草药与玉米- 豆粕型饲粮 Corn-soybean meal diet containing compound Chinese herbal medicine	枯草芽孢杆菌、植物乳杆菌、纤维素酶、蛋白酶、甘露聚糖酶、α-淀粉酶、葡聚糖酶	杜×长× 大猪	平均日增重为418 g,料重比为 1.55,腹泻指数为3.40,血清中IgG、 IgA、IgM含量分别为1.65、0.75、 0.19 g/L,血清中GSH-Px活性、 T-AOC、SOD活性分别为 483.60 μmol/L、58.64 U/mL、 198.69 U/mL	[71]
玉米-豆粕型饲粮 Corn-soybean meal diet	植物乳杆菌、戊糖片球菌、黑曲霉、蛋白酶、淀粉酶、脂肪酶、纤维素酶	杜×长× 大猪	平均日增重为473.75 g,料重比为1.52,腹泻率为6.55%,干物质、粗蛋白质和粗脂肪的消化率提高	[72]
玉米芯混合料 Maize cob mixed feed	发酵乳杆菌、酿酒酵母、枯草芽孢杆菌、非淀粉多糖酶	杜×长× 大猪	平均日增重为720.35 g,料重比为2.97,干物质、粗蛋白质和粗脂肪消化率分别为86.71%、 82.33%、63.15%,回肠中黏膜细胞因子含量和sIgA、IL-8、 TNF-α基因表达水平升高	[73]
玉米-豆粕型饲粮 Corn-soybean meal diet	芽孢杆菌、粪肠球菌、纤维素酶、甘露糖酶、果胶酶	杜×长× 大猪	平均日增重为419.58 g,料重比为1.51,腹泻率为7.56%	[74]

IgG:免疫球蛋白G immunoglobulin G;IgA:免疫球蛋白A immunoglobulin A;IgM:免疫球蛋白M immunoglobulin M;GSH-Px:谷胱甘肽过氧化物酶 glutathione peroxidase;T-AOC:总抗氧化能力 total antioxidant capacity;SOD:超氧化物歧化酶 superoxide dismutase;sIgA:分泌型免疫球蛋白A secretory immunoglobulin A;IL-8:白细胞介素-8 interleukin-8;TNF-α:肿瘤坏死因子-α tumor necrosis factor-α。下表同 the same as below。

4.2 在反刍动物生产中的应用

使用菌酶协同发酵高纤维饲料原料饲喂反刍动物,一方面可提高营养物质的表观消化率,另一方面可补充瘤胃益生菌,具体效果见表6。将鼠李糖乳杆菌和枝顶花纤维素酶添加到柱花草中发酵,能提高青贮饲料的发酵品质,尼龙袋法测定海南黑山羊对菌酶协同青贮柱花草的瘤胃降解率,结果表明该菌酶组合可能具有有益的协同作用^[75]。植物乳杆菌、布氏乳杆菌、纤维素酶、木聚糖酶、β-葡聚糖酶、果胶酶和漆酶密封发酵水稻秸秆45 d,配制精粗比为5∶5的全混合日粮,饲喂肉羊68 d,结果表明菌酶制剂的合理组合有利于促进肉羊对营养物质的消化利用,其效果达到或超过羊草水平^[76]。枯草芽孢杆菌、酵母菌、纤维素酶、葡聚糖酶和木聚糖酶塑封袋密封发酵金针菇菌糠12 d,在精料补充料中添加30%,饲喂湖羊60 d,可提高湖羊的生长性能、营养物质表观消化率和抗氧化能力^[77]。使用乳酸菌和纤维素酶发酵蜡熟期全株玉米,将其饲喂荷斯坦经产奶牛70 d,奶牛的采食量和泌乳量提高,牛乳品质和奶牛机体免疫功能得到改善^[78]。此外,使用益生菌(动物乳杆菌、费氏丙酸杆菌、地衣芽孢杆菌、枯草芽孢杆菌、屎肠球菌)和酶(淀粉酶、半纤维素酶和木聚糖酶)在模拟高产奶牛瘤胃环境的发酵罐中参与干燥粉碎的青贮玉米秸秆的消化,发酵罐发酵条件为39 ℃、连续注入氮气维持厌氧环境,3.05 mL/min的恒定速率注入人工唾液,丁酸盐的摩尔比例增加,而丙酸盐的摩尔比例下降,但没有导致体外瘤胃发酵发生重大改变^[79]。

表6 菌酶协同发酵饲料在反刍动物生产中的应用效果

Table 6 Application effects of synergistic fermented feeds of bacteria and enzymes in ruminant production

底物 Substrates	菌酶组合 Combination of bacteria and enzymes	品种 Breeds	效果 Effects	参考文献 References
柱花草 Stylosanthes guianensis	鼠李糖乳杆菌、枝顶花纤维素酶	海南黑山羊	瘤胃干物质降解率为51.37%,粗蛋白质降解率为50.12%,NDF降解率为 49.67%,ADF降解率为36.49%	[75]
水稻秸秆 Rice straw	植物乳杆菌、布氏乳杆菌、纤维素酶、木聚糖酶、β-葡聚糖酶、果胶酶、漆酶	杜泊×小尾寒羊杂交F1代	瘤胃干物质、NDF、ADF消化率分别提高38.40%、50.45%、91.97%	[76]
金针菇菌糠 Flammulina velutipes chaff	枯草芽孢杆菌、酵母菌、纤维素酶、葡聚糖酶、木聚糖酶	湖羊	平均日增重增加为165.83 g/d,料重比降低为7.78;干物质、粗蛋白质、NDF和 ADF表观消化率分别为74.83%、80.41%、 69.89%、59.54%;血清中GSH-Px、 SOD活性和T-AOC分别为174.23、 101.89和3.65 U/mL	[77]
全株玉米 Whole-plant corn	乳酸菌、纤维素酶	荷斯坦奶牛	采食量为25.26 kg/d,泌乳量为 31.45 kg/d,血清中IgA、IgG、 IgM含量升高	[78]

4.3 在家禽生产中的应用

菌酶协同发酵饲料在家禽生产中的应用效果见表7。给罗斯308肉鸡饲喂添加益生菌(包括罗伊氏乳杆菌、唾液乳杆菌、屎肠球菌、动物双歧杆菌、乳酸片球菌)+木聚糖酶组合的饲粮,饲喂21 d后,料重比和血清非酯化游离脂肪酸含量降低,肝糖原含量升高^[80]。将植物乳杆菌、酿酒酵母、甘露聚糖酶、纤维素酶和α-半乳糖苷酶添加在呼吸袋中,30 ℃协同发酵棕榈仁粕3 d,粗蛋白质含量提高了15.10%,粗纤维和NDF含量分别降低了25.10%和21.96%,17种氨基酸总量增加了7.12%,将最佳条件下发酵5 d的棕榈仁粕替代基础饲粮的15%后饲喂爱拔益加(AA)肉鸡7 d,其表观代谢能和16种氨基酸的标准回肠消化率增加^[81]。使用乳酸菌、酵母菌、芽孢杆菌、木聚糖酶、β-葡聚糖酶、甘露聚糖酶、纤维素酶和果胶酶协同发酵玉米-豆粕型饲粮5~7 d,将其饲喂河田肉鸡90 d,结果表明饲粮中添加5%菌酶协同发酵饲料有利于提高鸡肉风味物质含量,加强了氨基酸、次级产物及免疫功能等代谢通路基因的上调差异表达,改善了肠道菌群结构,对病原菌免疫、肠道健康起到了一定的作用^[82]。

表7 菌酶协同发酵饲料在家禽生产中的应用效果

Table 7 Application effects of synergistic fermented feeds of bacteria and enzymes in poultry production

底物 Substrates	菌酶组合 Combination of bacteria and enzymes	品种 Breeds	效果 Effects	参考文献 References
玉米-豆粕-干酒糟型饲粮 Corn-soybean meal- dried distillers grains diet	罗伊氏乳杆菌、唾液乳杆菌、屎肠球菌、动物双歧杆菌、乳酸片球菌、木聚糖酶	罗斯308肉鸡	日增重增加,饲料转化效率为1.67, 盲肠中丙酸和丁酸含量升高	[80]
棕榈仁粕 Palm kernel meal	植物乳杆菌、酿酒酵母、甘露聚糖酶、纤维素酶、 α-半乳糖苷酶	爱拔益加肉鸡	表观代谢能增加33.81%,16种氨基酸的标准回肠消化率增加5.48%	[81]
玉米-豆粕型饲粮 Corn-soybean meal diet	乳酸菌、酵母菌、芽孢杆菌、木聚糖酶、β-葡聚糖酶、甘露聚糖酶、纤维素酶、果胶酶	河田肉鸡	胸肌和腿肌中总氨基酸和风味氨基酸含量增加,乳杆菌属、乳球菌属、克里斯藤森菌科相对丰度增加,弯曲杆菌属、大肠杆菌-志贺菌群、密螺旋体属等病原菌相对丰度降低	[82]
豆粕和棉籽粕 Soybean meal and cottonseed meal	乳酸杆菌、酵母菌、纤维素酶、蛋白酶	京红1号蛋鸡	产蛋率为88.43%,平均蛋重为 61.7 g/枚,料蛋比为2.32,能量和粗蛋白质表观消化率提高,鸡粪中氨气浓度下降	[83]
玉米、豆粕、麸皮、糖蜜豆皮、米糠粕 Corn, soybean meal, bran, molasses bean hulls and rice bran meal	乳酸菌、酵母菌、芽孢杆菌、非淀粉多糖酶	京红1号蛋鸡	产蛋率为90.61%,平均蛋重为 58.15 g/枚,蛋黄中总单不饱和脂肪酸和总多不饱和脂肪酸含量提高	[84]

菌酶协同发酵饲料饲喂蛋鸡能提高鸡蛋品质,降低胆固醇含量。将乳酸杆菌、酵母菌、纤维素酶和蛋白酶协同发酵的饲料等蛋白质替代25%的豆粕蛋白质,饲喂京红蛋鸡49 d,改善了其生产性能和蛋品质,提高了养分表观消化率,降低了粪中氨气排放^[83]。使用乳酸菌、酵母菌、芽孢杆菌和非淀粉多糖酶发酵配合饲料,发酵菌株提前用红糖水活化,发酵原料与1%复合多维、0.07%非淀粉多糖酶和活化好的复合菌株共同混合,补充水分至30%,装入带单向透气孔的聚乙烯(PE)膜袋中密封,25 ℃发酵5~7 d,将该菌酶协同发酵饲料等量替代基础饲粮的5%,饲喂商品蛋鸡346 d,料蛋比、破蛋率以及蛋黄中脂肪和胆固醇含量显著降低,产蛋率、蛋黄比率和蛋壳强度显著提高,蛋黄中总饱和脂肪酸含量提高了4.75%,总单不饱和脂肪酸含量提高了2.63%,总多不饱和脂肪酸含量提高了18.24%^[84]。

5 小结

豆粕减量替代行动是国家粮食安全中的重要环节,非常规饲料原料的开发利用和现有饲料原料的高值化利用是替代畜禽饲粮中豆粕的主要途径,而利用益生菌(多种微生物)和工业生产的酶制剂协同青贮或发酵饲料原料是实现饲料原料高值化利用的重要方法,乳杆菌属、芽孢杆菌属、木质素过氧化物酶、纤维素酶和木聚糖酶等是常用的菌酶协同组合。反刍动物生产中主要使用的是高纤维饲料原料的菌酶协同发酵,单胃动物和家禽生产中主要使用的是全混合日粮或蛋白质饲料原料的菌酶协同发酵。菌酶协同发酵单一饲料原料或配合饲料可提高饲料营养价值和改善适口性,对畜禽生长性能和肠道微生物群落组成也具有积极作用。但菌酶协同发酵饲料的最适菌酶组合及其对畜禽生长性能和肠道微生物群落改变的具体机制还有待深入研究。

References

Publishing order | Descend order by publishing year | Descend order by cited within

[1]	孙智媛, 梅力文, 黄兴国, 等. 菌酶协同发酵饲料及其在动物生产中应用的研究进展[J]. 中国畜牧杂志, 2021, 57(8):42-47. SUN Z Y, MEI L W, HUANG X G, et al. Research progress on fermented feed by microbial cooperating with enzyme and its application to animal production[J]. Chinese Journal of Animal Science, 2021, 57(8):42-47. (in Chinese)

[2]	MENG Q S, ZHANG F, LIU C G, et al. Measurement of cellulase and xylanase activities in Trichoderma reesei[J]. Methods in Molecular Biology, 2021, 2234:135-146.

[3]	DU Z M, YAMASAKI S, OYA T, et al. Cellulase-lactic acid bacteria synergy action regulates silage fermentation of woody plant[J]. Biotechnology for Biofuels and Bioproducts, 2023, 16(1):125. DOI

[4]	BAI J, FRANCO M, DING Z T, et al. Effect of Bacillus amyloliquefaciens and Bacillus subtilis on fermentation,dynamics of bacterial community and their functional shifts of whole-plant corn silage[J]. Journal of Animal Science and Biotechnology, 2022, 13(1):7. DOI

[5]	JIANG Z C, GAO M, DING W, et al. Selective degradation and oxidation of hemicellulose in corncob to oligosaccharides:from biomass into masking agent for sustainable leather tanning[J]. Journal of Hazardous Materials, 2021, 413:125425. DOI

[6]	WU S S, WU S F. Processivity and the mechanisms of processive endoglucanases[J]. Applied Biochemistry and Biotechnology, 2020, 190(2):448-463. DOI PMID

[7]

GOURLAY

, HU

J G

, ARANTES

, et al. The use of carbohydrate binding modules (CBMs) to monitor changes in fragmentation and cellulose fiber surface morphology during cellulase- and Swollenin-induced deconstruction of lignocellulosic substrates[J]. Journal of Biological Chemistry, 2015, 290(5):2938-2945.

DOI PMID

[8]	BEYENE D, CHAE M, DAI J, et al. Characterization of cellulase-treated fibers and resulting cellulose nanocrystals generated through acid hydrolysis[J]. Materials, 2018, 11(8):1272. DOI

[9]	MOON M, LEE J P, PARK G W, et al. Lytic polysaccharide monooxygenase (LPMO)-derived saccharification of lignocellulosic biomass[J]. Bioresource Technology, 2022, 359:127501. DOI

[10]	WANG J P, QUIRK A, LIPKOWSKI J, et al. Real-time observation of the swelling and hydrolysis of a single crystalline cellulose fiber catalyzed by cellulase 7B from Trichoderma reesei[J]. Langmuir, 2012, 28(25):9664-9672. DOI

[11]	WARD N E. Debranching enzymes in corn/soybean meal-based poultry feeds:a review[J]. Poultry Science, 2021, 100(2):765-775. DOI

[12]	HEMATI A, NAZARI M, ASGARI LAJAYER B, et al. Lignocellulosics in plant cell wall and their potential biological degradation[J]. Folia Microbiologica, 2022, 67(5):671-681. DOI

[13]	TIEN M, KIRK T K. Lignin-degrading enzyme from Phanerochaete chrysosporium:purification,characterization,and catalytic properties of a unique H₂O₂-requiring oxygenase[J]. Proceedings of the National Academy of Sciences of the United States of America, 1984, 81(8):2280-2284.

[14]	CHU X D, AWASTHI M K, LIU Y Y A, et al. Studies on the degradation of corn straw by combined bacterial cultures[J]. Bioresource Technology, 2021, 320(Part A):124174.

[15]	YANG R, MENG D M, HU X S, et al. Saccharification of pumpkin residues by coculturing of Trichoderma reesei RUT-C30 and Phanerochaete chrysosporium Burdsall with delayed inoculation timing[J]. Journal of Agricultural and Food Chemistry, 2013, 61(38):9192-9199. DOI

[16]	JANUSZ G, PAWLIK A, ŚWIDERSKA-BUREK U, et al. Laccase properties,physiological functions,and evolution[J]. International Journal of Molecular Sciences, 2020, 21(3):966. DOI

[17]	LI X, ZHENG Y. Biotransformation of lignin:mechanisms,applications and future work[J]. Biotechnology Progress, 2020, 36(1):e2922. DOI

[18]	YANG J, YUE H R, PAN L Y, et al. Fungal strain improvement for efficient cellulase production and lignocellulosic biorefinery:current status and future prospects[J]. Bioresource Technology, 2023, 385:129449. DOI

[19]	ARAI T, ICHINOSE S, SHIBATA N, et al. Inducer-free cellulase production system based on the constitutive expression of mutated XYR1 and ACE3 in the industrial fungus Trichoderma reesei[J]. Scientific Reports, 2022, 12(1):19445. DOI

[20]	WANG H Y, PANG A P, LI B Z, et al. Intracellular sugar transporters facilitate cellulase synthesis in Trichoderma reesei using lactose[J]. Biomolecules, 2023, 13(2):295. DOI

[21]	HOU R R, HU J J, WANG Y Z, et al. Simultaneous production of cellulase and ferulic acid esterase by Penicillium decumbens with rice straw as the sole carbon source[J]. Journal of Bioscience and Bioengineering, 2020, 129(3):276-283. DOI

[22]	ŠUCHOVÁ K, FEHÉR C, RAVN J L, et al. Cellulose- and xylan-degrading yeasts:enzymes,applications and biotechnological potential[J]. Biotechnology Advances, 2022, 59:107981. DOI

[23]	BRODA M, POPESCU C M, CURLING S F, et al. Effects of biological and chemical degradation on the properties of scots pine wood-part Ⅰ:chemical composition and microstructure of the cell wall[J]. Materials, 2022, 15(7):2348. DOI

[24]	FASIKU S A, BELLO M A, ODENIYI O A. Production of xylanase by Aspergillus niger GIO and Bacillus megaterium through solid-state fermentation[J]. Access Microbiology, 2023, 5(6):acmi000506.v5.

[25]	MIAO T, BASIT A, LIU J Q, et al. Improved production of xylanase in Pichia pastoris and its application in xylose production from xylan[J]. Frontiers in Bioengineering and Biotechnology, 2021, 9:690702. DOI

[26]	AFTAB M, EJAZ U, PASHAMEAH R A, et al. Utilization of corncob as an immobilization matrix for a xylanolytic yeast strain[J]. Polymers, 2023, 15(3):683. DOI

[27]	AMADI O C, EGONG E J, NWAGU T N, et al. Process optimization for simultaneous production of cellulase,xylanase and ligninase by Saccharomyces cerevisiae SCPW 17 under solid state fermentation using Box-Behnken experimental design[J]. Heliyon, 2020, 6(7):e04566. DOI

[28]	FAVARO C P, BARALDI I J, CASCIATORI F P, et al. β-Mannanase production using coffee industry waste for application in soluble coffee processing[J]. Biomolecules, 2020, 10(2):227. DOI

[29]	LI D D, ZHANG Z, WANG J N, et al. Estimate of the degradation potentials of cellulose,xylan,and chitin across global prokaryotic communities[J]. Environmental Microbiology, 2023, 25(2):397-409. DOI

[30]	THOMAS L, RAM H, SINGH V P. Multipurpose cellulases of Promicromonospora sp. VP111,with broad substrate specificity and tolerance properties[J]. Journal of Basic Microbiology, 2023, 63(7):790-800. DOI

[31]	ALOKIKA, SINGH B. Enhanced production of bacterial xylanase and its utility in saccharification of sugarcane bagasse[J]. Bioprocess and Biosystems Engineering, 2020, 43(6):1081-1091. DOI PMID

[32]	ALGAN M, SÜRMELI Y, ŞANLI-MOHAMED G. A novel thermostable xylanase from Geobacillus vulcani GS90:production,biochemical characterization,and its comparative application in fruit juice enrichment[J]. Journal of Food Biochemistry, 2021, 45(5):e13716.

[33]	KETSAKHON P, THAMMASITTIRONG A, THAMMASITTIRONG S N R. Adding value to rice straw waste for high-level xylanase production using a new isolate of Bacillus altitudinis RS3025[J]. Folia Microbiologica, 2023, 68(1):87-99. DOI

[34]	DA SILVA VASCONCELOS RODRIGUES I, BARRETO J T, MOUTINHO B L, et al. Production of xylanases by Bacillus sp. TC-DT13 in solid state fermentation using bran wheat[J]. Preparative Biochemistry & Biotechnology, 2020, 50(1):91-97.

[35]	THITE V S, NERURKAR A S, BAXI N N. Optimization of concurrent production of xylanolytic and pectinolytic enzymes by Bacillus safensis M35 and Bacillus altitudinis J208 using agro-industrial biomass through response surface methodology[J]. Scientific Reports, 2020, 10(1):3824. DOI

[36]	YANG H Z, HE R Y, CUI Y, et al. Saprophytic Bacillus accelerates the release of effective components in agarwood by degrading cellulose[J]. Molecules, 2022, 27(4):1428. DOI

[37]	LI Y X, KURAMAE E E, NASIR F, et al. Addition of cellulose degrading bacterial agents promoting keystone fungal-mediated cellulose degradation during aerobic composting:construction the complex co-degradation system[J]. Bioresource Technology, 2023, 381:129132. DOI

[38]	ZHANG X, BORJIGIN Q, GAO J L, et al. Community succession and straw degradation characteristics using a microbial decomposer at low temperature[J]. PLoS One, 2022, 17(7):e0270162. DOI

[39]	KHADKA S, KHADKA D, POUDEL R C, et al. Production optimization and biochemical characterization of cellulase from Geobacillus sp. KP43 isolated from hot spring water of Nepal[J]. BioMed Research International, 2022, 2022:6840409.

[40]	RAJESH R, GUMMADI S N. α-amylase and cellulase production by novel halotolerant Bacillus sp. PM06 isolated from sugarcane pressmud[J]. Biotechnology and Applied Biochemistry, 2022, 69(1):149-159. DOI

[41]	DAWOOD A, MA K S. Applications of microbial β-mannanases[J]. Frontiers in Bioengineering and Biotechnology, 2020, 8:598630. DOI

[42]	SUN Y C, ZHOU X H, ZHANG W, et al. Enhanced β-mannanase production by Bacillus licheniformis by optimizing carbon source and feeding regimes[J]. Preparative Biochemistry & Biotechnology, 2022, 52(7):845-853.

[43]	BLIBECH M, FARHAT-KHEMAKHEM A, KRIAA M, et al. Optimization of β-mannanase production by Bacillus subtilis US191 using economical agricultural substrates[J]. Biotechnology Progress, 2020, 36(4):e2989. DOI

[44]	ROMAIN B, DELVIGNE F, RÉMOND C, et al. Control of phenotypic diversification based on serial cultivations on different carbon sources leads to improved bacterial xylanase production[J]. Bioprocess and Biosystems Engineering, 2022, 45(8):1359-1370. DOI

[45]	LI P P, HE C, LI G, et al. Biological pretreatment of corn straw for enhancing degradation efficiency and biogas production[J]. Bioengineered, 2020, 11(1):251-260. DOI PMID

[46]	ZHANG S T, DONG Z J, SHI J, et al. Enzymatic hydrolysis of corn stover lignin by laccase,lignin peroxidase,and manganese peroxidase[J]. Bioresource Technology, 2022, 361:127699. DOI

[47]	GRANJA-TRAVEZ R S, PERSINOTI G F, SQUINA F M, et al. Functional genomic analysis of bacterial lignin degraders:diversity in mechanisms of lignin oxidation and metabolism[J]. Applied Microbiology and Biotechnology, 2020, 104(8):3305-3320. DOI

[48]	MEI J F, SHEN X B, GANG L P, et al. A novel lignin degradation bacteria-Bacillus amyloliquefaciens SL-7 used to degrade straw lignin efficiently[J]. Bioresource Technology, 2020, 310:123445. DOI

[49]	SINGH B, KUMAR G, KUMAR V, et al. Enhanced phytase production by Bacillus subtilis subsp. subtilis in solid state fermentation and its utility in improving food nutrition[J]. Protein & Peptide Letters, 2021, 28(10):1083-1089.

[50]	TANRUEAN K, PENKHRUE W, KUMLA J, et al. Valorization of lignocellulosic wastes to produce phytase and cellulolytic enzymes from a thermophilic fungus,Thermoascus aurantiacus SL16W,under semi-solid state fermentation[J]. Journal of Fungi, 2021, 7(4):286. DOI

[51]	CHANDRA P, ENESPA, SINGH R, et al. Microbial lipases and their industrial applications:a comprehensive review[J]. Microbial Cell Factories, 2020, 19(1):169. DOI

[52]	KIELISZEK M, POBIEGA K, PIWOWAREK K, et al. Characteristics of the proteolytic enzymes produced by lactic acid bacteria[J]. Molecules, 2021, 26(7):1858. DOI

[53]	HAILE S, AYELE A. Pectinase from microorganisms and its industrial applications[J]. The Scientific World Journal, 2022, 2022:1881305.

[54]	KIKANI B A, SINGH S P. Amylases from thermophilic bacteria:structure and function relationship[J]. Critical Reviews in Biotechnology, 2022, 42(3):325-341. DOI

[55]	QI Z Y, WANG B W, SUN C, et al. Comparison of properties of poly(lactic acid) composites prepared from different components of corn straw fiber[J]. International Journal of Molecular Sciences, 2022, 23(12):6746. DOI

[56]	LV J S, LIU X Y, ZHANG X P, et al. Chemical composition and functional characteristics of dietary fiber-rich powder obtained from core of maize straw[J]. Food Chemistry, 2017, 227:383-389. DOI

[57]	徐晓东, 吴立坡, 姜宁, 等. 复合菌酶制剂对玉米秸秆黄贮发酵品质的影响[J]. 中国畜牧杂志, 2021, 57(9):187-191. XU X D, WU L P, JIANG N, et al. Effect of compound bacterial enzyme preparation on the quality of corn straw storage and fermentation[J]. Chinese Journal of Animal Science, 2021, 57(9):187-191. (in Chinese)

[58]

任海伟, 石瑞锋, 魏慧元, 等. 菌/酶添加对甜高粱渣青贮预处理作用的强化效果[J]. 农业工程学报, 2023, 39(6):224-236.

REN

H W

, SHI

R F

, WEI

H Y

, et al. Improvement for the ensiling pretreatment effectiveness of sweet sorghum bagasse by fortified with Lactobacillus plantarum and cellulolytic enzymes[J]. Transactions of the Chinese Society of Agricultural Engineering, 2023, 39(6):224-236. (in Chinese)

[59]	WANG Q D, WANG R X, WANG C Y, et al. Effects of cellulase and Lactobacillus plantarum on fermentation quality,chemical composition,and microbial community of mixed silage of whole-plant corn and peanut vines[J]. Applied Biochemistry and Biotechnology, 2022, 194(6):2465-2480. DOI

[60]	王乐乐, 秦荣艳, 阿不夏合满·穆巴拉克, 等. 菌酶协同发酵香菇菌糠复合制剂的筛选研究[J]. 饲料研究, 2022, 45(17):58-63. WANG L L, QIN R Y, MUBALAKE A B X H M, et al. Study on screening of compound preparation of Lentinus edoides chaff fermented by bacterial enzyme[J]. Feed Research, 2022, 45(17):58-63. (in Chinese)

[61]	李家明, 张玉鹏, 汪腾蛟, 等. 菌酶协同发酵对辣木茎秆粉的营养成分和植酸含量的影响[J]. 饲料研究, 2021, 44(3):69-72. LI J M, ZHANG Y P, WANG T J, et al. Effect of bacterial enzyme synergistic fermentation on nutritional composition and phytic acid content of Moringa oleifera stem powder[J]. Feed Research, 2021, 44(3):69-72. (in Chinese)

[62]	SI Q, WANG Z J, LIU W, et al. Influence of cellulase or Lactiplantibacillus plantarum on the ensiling performance and bacterial community in mixed silage of alfalfa and Leymus chinensis[J]. Microorganisms, 2023, 11(2):426. DOI

[63]	HE L W, ZHOU W, WANG C, et al. Effect of cellulase and Lactobacillus casei on ensiling characteristics,chemical composition,antioxidant activity,and digestibility of mulberry leaf silage[J]. Journal of Dairy Science, 2019, 102(11):9919-9931. DOI

[64]	QI N S, ZHAN X S, MILMINE J, et al. Isolation and characterization of a novel hydrolase-producing probiotic Bacillus licheniformis and its application in the fermentation of soybean meal[J]. Frontiers in Nutrition, 2023, 10:1123422. DOI

[65]	荀冉, 卢艳波, 杨小雁, 等. 基于抗原蛋白评价的豆粕菌酶协同发酵研究[J]. 食品与发酵工业, 2023, 49(19):127-134. DOI XUN R, LU Y B, YANG X Y, et al. A study on bacterial enzyme synergistic fermentation of soybean meal based on antigenic protein evaluation[J]. Food and Fermentation Industries, 2023, 49(19):127-134. (in Chinese) DOI

[66]	陈敬帮, 戴晋军, 徐智鹏, 等. 菌酶固态发酵豆粕去除抗营养因子的差异化研究[J]. 中国饲料, 2022(21):147-150. CHEN J B, DAI J J, XU Z P, et al. Study on the synergistic effect of microorganism and enzymes on the removal of anti-nutritional factors in solid-state fermented soybean meal[J]. China Feed, 2022(21):147-150. (in Chinese)

[67]	HARIHARAN S, PATTI A, ARORA A. Functional proteins from biovalorization of peanut meal:advances in process technology and applications[J]. Plant Foods for Human Nutrition, 2023, 78(1):13-24. DOI

[68]	周佳慧, 李晓敏, 蔡国林, 等. 菌酶协同改善花生粕的饲用品质[J]. 中国油脂, 2021, 46(9):92-98. ZHOU J H, LI X M, CAI G L, et al. Synergistic of enzymes and fermentation to improve the feed quality of peanut meal[J]. China Oils and Fats, 2021, 46(9):92-98. (in Chinese)

[69]	张倩茹, 安晓萍, 王园, 等. 菌酶协同发酵玉米芯制备木聚糖的研究[J]. 中国饲料, 2017(22):23-26. ZHANG Q R, AN X P, WANG Y, et al. Study on preparation of xylan by enzymatic fermentation of corncob[J]. China Feed, 2017(22):23-26. (in Chinese)

[70]	商子涵, 贾琳, 石建存, 等. 菌酶协同发酵中药饲料添加剂的工艺优化[J]. 饲料研究, 2022, 45(4):67-70. SHANG Z H, JIA L, SHI J C, et al. Fermentation process optimization of traditional Chinese medicine feed additives by microbial enzyme[J]. Feed Research, 2022, 45(4):67-70. (in Chinese)

[71]

姜玫宏, 葛金山, 程金龙, 等. 菌酶协同异步发酵中草药对断奶仔猪生长、腹泻、免疫和抗氧化性能的影响[J]. 江苏农业学报, 2023, 39(1):126-133.

JIANG

M H

, GE

J S

, CHENG

J L

, et al. Effects of bacteria-enzymes synergistic asynchronous fermentation of Chinese herbal medicine on growth,diarrhea,immunity and antioxidant of weaned piglets[J]. Jiangsu Journal of Agricultural Sciences, 2023, 39(1):126-133. (in Chinese)

[72]

冯江鑫, 陈代文, 余冰, 等. 菌酶协同发酵饲粮对仔猪生长性能、养分消化率、血清生化指标和肠道屏障功能的影响[J]. 动物营养学报, 2020, 32(3):1099-1108.

DOI

FENG

J X

, CHEN

D W

, YU

, et al. Effects of diets fermented with bacteria and enzyme on growth performance,nutrient digestibility,serum biochemical indices and intestinal barrier function of piglets[J]. Chinese Journal of Animal Nutrition, 2020, 32(3):1099-1108. (in Chinese)

[73]	LIN B S, YAN J B, ZHONG Z L, et al. A study on the preparation of microbial and nonstarch polysaccharide enzyme synergistic fermented maize cob feed and its feeding efficiency in finishing pigs[J]. BioMed Research International, 2020, 2020:8839148.

[74]

张煜, 石常友, 王成, 等. 菌酶协同发酵改善玉米-豆粕型饲料营养价值的研究[J]. 中国粮油学报, 2018, 33(3):70-77.

ZHANG

, SHI

C Y

, WANG

, et al. Improving nutrition value of maize-soybean meal based diet by microbial fermentation combined with multiple-enzymes[J]. Journal of the Chinese Cereals and Oils Association, 2018, 33(3):70-77. (in Chinese)

[75]	LI M, ZHOU H L, ZI X J, et al. Silage fermentation and ruminal degradation of stylo prepared with lactic acid bacteria and cellulase[J]. Animal Science Journal, 2017, 88(10):1531-1537. DOI PMID

[76]	冯文晓, 陶莲, 陈国顺, 等. 菌酶处理水稻秸秆对肉用绵羊营养物质表观消化率与血清生化指标的影响[J]. 中国饲料, 2017(11):9-14. FENG W X, TAO L, CHEN G S, et al. Effects of bacterial enzyme treating rice straw on nutrient digestibility and serum biochemical indexes of mutton sheep[J]. China Feed, 2017(11):9-14. (in Chinese)

[77]

康永刚, 孙朋, 廖云琼, 等. 菌酶协同发酵金针菇菌糠对湖羊生长性能、营养物质的表观消化率及抗氧化能力的影响[J]. 饲料研究, 2022, 45(21):24-28.

KANG

Y G

, SUN

, LIAO

Y Q

, et al. Effect of fermented Flammulina velutiper chaff by bacteria coupled with enzymes on growth performance,nutrient apparent digestibility and antioxidant capacity of Hu sheep[J]. Feed Research, 2022, 45(21):24-28. (in Chinese)

[78]

王璐, 曲永利, 辛小月, 等. 饲喂菌制剂与菌酶制剂处理的全株玉米青贮对泌乳奶牛生产性能和血液免疫指标的影响[J]. 中国畜牧杂志, 2019, 55(11):142-145.

WANG

, QU

Y L

, XIN

X Y

, et al. Effects of feeding whole-plant corn silage treated with bacterial preparations and bacterial enzyme preparations on production performance and blood immune indicators of lactating dairy cows[J]. Chinese Journal of Animal Science, 2019, 55(11):142-145. (in Chinese)

[79]	BENNETT S L, ARCE-CORDERO J A, BRANDAO V L N, et al. Effects of bacterial cultures,enzymes,and yeast-based feed additive combinations on ruminal fermentation in a dual-flow continuous culture system[J]. Translational Animal Science, 2021, 5(2):txab026. DOI

[80]	MURUGESAN G R, PERSIA M E. Influence of a direct-fed microbial and xylanase enzyme on the dietary energy uptake efficiency and performance of broiler chickens[J]. Journal of the Science of Food and Agriculture, 2015, 95(12):2521-2527. DOI PMID

[81]	王卫卫, 邓雪娟, 李冲, 等. 菌酶协同处理对棕榈仁粕营养价值的影响[J]. 饲料工业, 2023, 44(10):31-38. WANG W W, DENG X J, LI C, et al. Effect of synergistic treatment by probiotics and enzymes on nutritional value of palm kernel cake[J]. Feed Industry, 2023, 44(10):31-38. (in Chinese)

[82]

林标声, 何玉琴, 谢璐娜, 等. 菌酶协同发酵饲料对肉鸡肌肉风味物质含量、肠道转录组及菌群组成的影响[J]. 动物营养学报, 2022, 34(11):7049-7062.

DOI

LIN

B S

, HE

Y Q

, XIE

L N

, et al. Effects of fermented feed by bacteria coupled fermentation with enzymes on meat flavor contents,intestinal transcriptome and flora composition of broilers[J]. Chinese Journal of Animal Nutrition, 2022, 34(11):7049-7062. (in Chinese)

[83]

刘闰, 赵国先, 刘观忠, 等. 菌酶协同发酵饲料对蛋鸡生产性能、养分表观消化率和粪中氨气排放的影响[J]. 饲料研究, 2022, 45(18):29-33.

LIU

, ZHAO

G X

, LIU

G Z

, et al. Effect of fermented feed by microbial cooperating with enzyme on production performance,nutrient apparent digestibility and ammonia excretion in fecal of laying hens[J]. Feed Research, 2022, 45(18):29-33. (in Chinese)

[84]

林标声, 何玉琴, 谢璐娜, 等. 菌酶协同发酵饲料对商品蛋鸡生产性能和蛋品质的影响[J]. 黑龙江畜牧兽医, 2022(21):99-103.

LIN

B S