假单胞菌B41产果胶酶发酵条件的研究

对假单胞菌B41发酵产果胶酶培养基和发酵培养条件进行了优化。经单因素和正交试验得到最优发酵培养基组成为桔皮粉20．0g／L,蛋白胨10．0g／L,FeSO40．5g／L,初始pH值5．5。最佳发酵条件为装液量50mL,接种量2％,发酵温度30％,发酵时间32h。在此优化条件下,果胶酶活力为739U／mL。     

水稻秸秆同步糖化发酵生产燃料乙醇的研究

研究了培养基起始pH、发酵时间、发酵温度、酵母接种量和吐温80对水稻秸秆同步糖化发酵产乙醇的影响。结果表明,酵母接种量能有效地提高发酵液中乙醇的产率。水稻秸秆同步糖化发酵生产燃料乙醇的适宜发酵工艺条件为：起始pH值为4．0～4．5,培养温度为32℃,接种量为12％,发酵时间12-24h。在此条件下,生成乙醇的浓度为1．4mg／mL,水稻秸秆原料的乙醇转化率达7．02％。     

凝结芽孢杆菌CICIM B1821发酵生产L-乳酸的研究

凝结芽孢杆菌（Bacillus coagulans）CICIM B1821是一株实验室前期筛选获得的产L-乳酸的嗜热菌。该菌株在34～55℃范围内均表现出良好的生长特性和产酸特性,50℃时获得最高的比生长速率和最大的乳酸积累量。CICIMB1821能够在pH为5．0～7．5的范围内保持高的菌体活性。氧气的存在有利于CICIMB1821的快速生长．但会导致副产物的积累,而在不通氧的条件下该菌株也生长良好,同时产酸速率可高达5．63g／L·h。控制残糖浓度不高于10％的发酵条件下,发酵48h,可积累乳酸107．5g／L,副产物总和仅为1．05g／L,葡萄糖对乳酸的得率为97．5％,所产L-乳酸光学纯度高于99％。此外,高浓度葡萄糖发酵实验显示,该菌株可在高渗透压下利用20％葡萄糖发酵生产L-乳酸,发酵100h．可积累乳酸134g／L,副产物总和仅为1．12g／L,葡萄糖对乳酸的得率为92．0％。     

哈密大枣果酒发酵工艺的研究

采用新疆特产哈密大枣作为原料,选择丹宝利酵母菌作为发酵用菌种。考察发酵温度、初始糖度、菌种接种量、pH和发酵时间对发酵的影响,并在此基础上进行了优化实验。结果表明,在接种量0．12％,初始糖度为14％,发酵温度32℃,发酵时间96h条件下,酒精含量接近8．0％vol,残糖含量仅为376．5mg／100g。     

菊粉酶基因重组酵母菌水解蔗糖的研究

表达蔗糖酶活性的菊粉酶基凶工程菌株GS115／INU1，经甲醇诱导发酵72h蔗糖酶活力为119．8U／mL。该酶水解蔗糖最适温度为55％、最适pH值为4．5。50％蔗糖溶液，加酶量12．0U／g底物、水解6h，蔗糖水解率达到89．5％。     

真菌固态发酵预处理大豆高效提油的初步研究

利用黄曲霉和黑曲霉固态发酵大豆,通过测定还原糖和氨态氮含量的变化．判断真菌对营养成分的利用情况与油脂提取效果的关系。结果表明：在3h的提油时间里．大豆经黑曲霉和黄曲霉固态发酵预处理后,分别在发酵96h和72h达到最大提油量,为23％（w／w）和21．6％（w／w）,比对照组（15．6％,w／w）分别提高47．4%和38．5％,提油量都有很明显的提高。对发酵前后油脂的酸值和过氧化值测定结果表明：发酵后油脂的酸值和过氧化值均高于未发酵的油脂．     

乳酸发酵鲜菇汁技术研究

以鲜菇汁为原料，经乳酸发酵而制成鲜菇汁发酵饮料，通过对接种量、发酵时间、乳粉量、糖酸比进行试验．从而确定最佳工艺参数为：接种量3％，乳粉量5％，发酵时间3．75h，蔗糖12％，柠檬酸0．04％。     

基于基质需求特征确立脱氮假单胞杆菌产维生素B12的发酵原料

对于工业化发酵而言,选择一种适宜的发酵原料对提高微生物发酵产量及降低发酵成本显得尤为重要.该文首先在合成培养基中考察了氨基酸对脱氮假单胞杆菌合成维生素B12的影响,结果表明谷氨酸等氨基酸对菌体生长和维生素B12合成具有较大的促进作用.甜菜糖蜜作为制糖工业的副产物,其成本相对低廉,但营养组分检测显示,甜菜糖蜜含有丰富的碳源和有机氮类物质,其中有机氮类又以谷氨酸居多,而且还含有一定量的合成维生素B12所必需的甲基供体甜菜碱.基于此,最终确立了以甜菜糖蜜作为维生素B12发酵的主要原料.在该原料下,脱氮假单胞杆菌摇瓶发酵结束时(168h)的菌体量(光密度)和维生素B12产量分别达到37.3mg/L和108.37mg/L.     

蔗汁酒精发酵中酵母菌株筛选及发酵工艺优化

以甘蔗汁为培养基比较CICC1308、As2．1190、广西贵糖4608、As2．109（GIM2．34）和R12（GIM2．84）五株酿酒酵母的酒精发酵特性。通过酒精耐受性及发酵能力测试,选出适合蔗汁酒精发酵的菌株为CICC1308。通过CICC1308菌株发酵工艺的单因素试验对发酵液原始pH值、发酵温度、接种量及发酵时间进行优化。结果表明：发酵液原始pH值5．0、发酵温度30~C、接种量15％（v／v）和发酵时间60h为最优条件试验,酒精产率可达92．15％。     

红曲霉液态法生产红色素发酵条件的优化

研究了菌株紫红曲霉No．1-18-54液态发酵产红色素的发酵条件。结果表明，适宜的发酵条件为起始pH6．0，摇瓶装料量20mL／250mL三角瓶，接菌种龄48h，接种量10％（v／v），发酵温度30℃，摇床转速180r／min，发酵周期132h。实验研究还发现在发酵培养基中添加0．2％味精有利于红色素的生成，平均色价为66．7U／mL。     

枯草芽孢杆菌C3产抗菌物质发酵条件优化

利用筛选的枯草芽孢杆菌(Bacillus subtilis)C3研究提高产抗菌物质的发酵条件。通过测定枯草芽孢杆菌C3抗菌物质对黑曲霉孢子萌发的抑制率,设计6因素3水平正交试验得到优化的发酵条件为:种子液的菌龄12h,种子液接种量2%,发酵培养基装液量75mL/250mL,发酵培养基初始pH 7.0,发酵温度37℃,发酵时间48h。在优化发酵条件下,枯草芽孢杆菌C3产抗菌物质的抑菌活性比优化前提高了26.52%。     

Growth and metabolism of selected strains of probiotic bacteria in milk

Growth and metabolism of five probiotic strains with well-documented health effects were studied in ultra-high temperature (UHT) treated milk, supplemented with 0.5% (w/v) tryptone or 0.75% (w/v) fructose. The probiotic strains were Lactobacillus acidophilus La5, Lb. acidophilus 1748, Lactobacillus rhamnosus GG, Lactobacillus reuteri SD 2112 and Bifidobacterium animalis BB12. Fermentation was followed for 72 h at 37 degrees C and the samples were analysed for pH, log cfu ml(-1), volatile compounds, organic acids and carbon dioxide. The strains reduced pH from 6.7 to between 3.9 and 4.4 after 24 h of incubation. All strains attained viable cell counts above 8.7-9.18 log cfu ml(-1) after 6-16 h of incubation. The two Lb. acidophilus strains showed a stable level of viable cells during 12-72 h of incubation but the three other strains showed a reduction of 0.4-1.1 log cfu ml(-1) from 24 to 72 h of incubation. However, all strains showed cell levels between 7.8 and 8.7 log cfu ml(-1) after 72 h of incubation. After 48 h of incubation, the amount of lactic acid produced varied according to strain from 6949 to 14,000 mg kg(-1) and acetic acid produced varied from 0 to 6901 mg kg(-1). Three of the strains metabolised citrate but only low amounts of diacetyl and acetoin were detected within strains, 0.2-0.8 and 6.5-10 mg kg(-1), respectively. Carbon dioxide produced varied from 221 to 3942 mg kg(-1) and was connected to the citrate-fermenting ability of the strain used and their carbohydrate fermentation pathway. Three of the strains produced detectable levels of acetaldehyde and the concentration varied from 9.4 to 12.6 mg kg(-1) after 24 h of incubation. All five probiotic strains showed very different profiles of metabolites during fermentation; however, the two Lb. acidophilus strains were the most alike. Our findings show the importance of controlling the fermentation time since the probiotic strains produced different amounts of metabolic products according to fermentation time.     

中国根霉12菌株抗生物质产生条件和性质

中国根霉（ＲｈｉｚｏｐｕｓＣｈｉｎｅｓｉｓ）１２能产生一种对芽孢菌属细菌有独特抑制作用的抗生物质。其发酵条件研究结果表明：在以正交实验确定的最佳培养基（豆饼粉酶解液８０ｍｌ、玉米粉水解液２０ｍｌ、葡萄糖２ｇ、ｐＨ自然）和最适发酵工艺条件（种龄１８ｈ、接种量１％、发酵培养基初始ｐＨ６．０～６．５、装液量５０ｍｌ／２５０ｍｌ三角瓶，摇床转速１６０ｒ／ｍｉｎ、２８～３０℃培养４８ｈ）下，Ｒ．ｃｈｉｎｅｓｉｓ１２菌株产生的抗生物质的抑菌圈直径为２１．５ｍｍ，抑菌面积３０９．３６ｍｍ２，是对照少孢根霉（Ｒ．ｏｌｉｇｏｓｐｏｒｕｓ）ＩＦＯ８６３１菌株的６倍。该物质可被胰蛋白酶所破坏，由纸电泳和茚三酮反应等实验结果判定该抗生物质为碱性多肽或蛋白质性质的物质。     

响应面法优化欧李果汁与牛奶复合益生菌饮料发酵工艺

以欧李（Cerasus humilis）果汁与牛奶为主要原料制作复合益生菌饮料,以总抗氧化能力和活菌数为评价指标,经单因素试验分析发酵菌株、果浆浓度、脱脂牛奶添加量、糖度、接种量和发酵时间对发酵饮料的影响,并通过响应面试验对影响较大的4个因素进行优化,确定复合益生菌饮料最佳工艺。结果表明,最佳发酵工艺为发酵菌株植物乳杆菌（Lactobacillus plantarum）和嗜酸乳杆菌（Lactobacillus acidophilus）（1∶1）,欧李果汁添加量49%,脱脂牛奶添加量12.3%,糖度12 °Bx,接种量6%,发酵时间41 h。在此优化发酵工艺条件下,饮料总抗氧化能力为143.33 U/mL,活菌数为8.70 lg（CFU/mL）,色泽鲜艳呈粉红色,气味纯正,具有欧李果香,酸甜可口,滋味宜人。     

产褐藻胶裂解酶弧菌HB161653的产酶条件优化

为提高弧菌HB161653产褐藻胶裂解酶活性,该研究通过单因素和正交试验对弧菌HB161653的产酶条件进行了优化。结果表明,最优的发酵培养基组成为海藻酸钠5 g/L,蛋白胨7.5 g/L,NaCl 25 g/L,K2HPO4 0.2 g/L,MgSO4 0.1 g/L;最优发酵条件为培养基初始pH 7.0,接种量1.5%,发酵温度28 ℃,发酵周期12 h。在此优化产酶条件下,褐藻胶裂解酶活力可达42.1 U/mL,较优化前（26.0 U/mL）提高了62%。该研究可为弧菌HB161653产褐藻胶裂解酶的规模化生产和褐藻寡糖的制备提供理论依据。     

芽孢杆菌混合发酵工艺条件的优化

为提高饲料用芽孢杆菌中性蛋白酶的活力,考察了多种芽孢杆菌混菌发酵产蛋白酶的协同作用效果,并在单因素试验的基础上,采用响应面分析的中心组合试验设计对多芽孢杆菌的混合发酵工艺条件进行了优化。通过优化确定了混合发酵体系的最佳发酵条件为培养基最初pH值7.17,装液量50mL/250mL,接种量3%,发酵温度35.4℃,摇床转速200r/min,发酵周期100h。在优化的工艺条件下,芽孢杆菌混合发酵产蛋白酶的活力单位可达到2 986U/mL。     

桑黄风味酸奶发酵工艺优化

该试验以桑黄发酵液、脱脂奶粉为主要原料,将保加利亚乳杆菌、嗜热链球菌、乳双歧杆菌1∶1∶1混合作为发酵菌剂,生产桑黄酸奶。通过单因素试验和正交试验分别考察桑黄发酵液添加量、奶粉添加量、白砂糖添加量、发酵菌剂接种量、发酵时间和发酵温度对桑黄风味酸奶品质的影响。结果表明,桑黄风味酸奶的最佳发酵工艺条件为桑黄发酵液添加量15 mL/100 mL、奶粉添加量17 g/100 mL、白砂糖添加量7 g/100 mL、发酵菌剂（8.4×108 CFU/mL）接种量5 mL/100 mL、发酵时间5 h、发酵温度42 ℃。在此优化条件下,制备的桑黄风味酸奶感官评分为92.2分,蛋白质和脂肪含量分别为1.86 g/100 g、0.6 g/100 g、1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除率为46%。     

Functional properties of curry paste in relation to digestibility and fermentation by gut microbiota

The prebiotic properties of sour curry paste in the upper gut and the gut microbiota were investigated in vivo during digestion. The effect of the addition of garcinia as souring agent in curry paste was studied. Curry paste without garcinia (P1) and curry paste with garcinia (P2) increased the number of beneficial bacteria in the gut microbiota, especially bifidobacteria and lactobacilli, and significantly (p < 0.05) decreased the number of harmful bacteria (Clostridia). Fecal fermentation with P1 resulted in a prebiotic index (PI) of 1.19, whereas fermentation with P2 resulted in a PI of 2.75. The fermented metabolites produced were lactic acid; vitamins; and short-chain fatty acids (SCFAs) such as acetic acid, propionic acid, and butyric acid. P1 produced metabolites including lactic acid, SCFAs, and B vitamins in higher amounts than P2. After a 24 h fermentation period with colonic microbiota, P1 produced vitamins B1 (18.38 ± 0.10 µg/ml) and B2 (45.28 ± 2.02 µg/ml) but not folic acid, whereas P2 produced only vitamin B1 (5.99 ± 0.48 µg/ml).     

Production of ethanol from liquefied cassava starch using co-immobilized cells of Zymomonas mobilis and Saccharomyces diastaticus

Co-immobilized cells of Saccharomyces diastaticus and Zymomonas mobilis produced a high ethanol concentration compared to immobilized cells of S. diastaticus during batch fermentation of liquefied cassava starch. The co-immobilized cells produced 46.7 g/l ethanol from 150 g/l liquefied cassava starch, while immobilized cells of yeast S. diastaticus produced 37.5 g/l ethanol. The concentration of ethanol produced by immobilized cells was higher than that by free cells of S. diastaticus and Z. mobilis in mixed-culture fermentation. In repeated-batch fermentation using co-immobilized cells, the ethanol concentration increased to 53.5 g/l. The co-immobilized gel beads were stable up to seven successive batches. Continuous fermentation using co-immobilized cells in a packed bed column reactor operated at a flow rate of 15 ml/h (residence time, 4 h) exhibited a maximum ethanol productivity of 8.9 g/l/h.