香蕉及茶叶中纤维素酶产生菌的筛选

本实验从香蕉茎叶、茶叶及香蕉土壤、茶土壤环境中经初筛和复筛分离纯化出16株产纤维素酶的菌株,对其菌株的外在特性和产酶活力进行了研究和测定。结果从培养基来看,产酶菌株以从牛肉膏蛋白胨中性培养基里分离出来的为最多（5株）;体原料来源,以从土壤环境中分离出的菌株居多（10株）。菌株多为乳黄色（8株）和蓝绿色霉菌（3株）。水解圈以半透明的居多（12株）,且16株菌株的水解圈与菌落直径比在1.0-2．0之间居多（10株）。产酶菌株的酶活和水解圈的透明状态基,树目符,即水解圈为透明状态的菌株酶活值较大,而水解圈为半透明状态的菌株酶活值相对较小;其中以查中香土10^-2-2-1的酶活值最大,为4．5。     

石榴皮单宁降解菌株的筛选

从石榴皮、石榴茎叶、石榴土壤中经初筛分离纯化出17株产单宁酸酶菌株，并对菌株的菌落特征和COD去除率进行了研究和测定。结果表明：产酶菌株以从查氏中性培养基里分离出来的居多（15株）；菌株多为黑色霉菌；菌株的水解圈与菌落直径比均在1．0-2．0之间；水解圈直径越大的菌株COD去除率越高，水解圈为透明状态的菌株COD去除率越高；通过对菌株菌落形态特征的观察及菌株COD去除率的测定，筛选出7#（查中皮3-3）、9#（查中皮4-3）为目标菌株。     

海洋细菌产低温碱性蛋酶菌株的筛选研究

采集连云港黄海海域的各类海鱼和贝类及海水等样品，采用富集培养、干酪素培养基及水解酪蛋白试验分离产蛋白酶的菌株。结果表明从海鱼、海贝等样品中能得到产低温碱性蛋白酶的菌株；干酪素分离培养基是较好的筛选培养基，产酶菌株都能在干酪素培养基上产生透明圈；水解酪蛋白试验可对菌株的产酶情况进行定性研究，酶活较高的菌株都能产生较大的水解圈。干酪素分离培养基配合水解酪蛋白试验进行产低温碱性蛋白酶菌株的筛选，可以提高筛选效率。     

产几丁质降解酶菌株的筛选及其产酶条件

采用平板透明圈法从土壤中分离筛选到一株产几丁质降解酶菌株L12酶活力为0．63U／mL。通过产酶条件优化，初步确定了该菌株较适产酶培养基和摇瓶发酵条件。条件优化后酶活力提高约1．6倍，达到1．06U／mL。     

产纤维素酶细菌的微波诱变及产酶条件的研究

以实验室保藏的产纤维素酶芽孢杆菌S（3）7为出发菌,对其进行微波诱变处理,采用透明圈法初筛和液体摇瓶发酵复筛,得到一株产纤维素酶活力较高的突变菌株S（3）7-5。对该突变菌株的产酶条件进行研究,结果表明,突变菌株最适产酶条件为：发酵温度37℃,起始pH9．0,发酵时间4d。在此条件下,该突变菌株所产纤维素酶活最高,达52．55U／mL,比出发菌株的产酶活力提高了26．6％。     

^60Coγ—DES复合诱变选育高产中性蛋白酶枯草杆菌及其发酵工艺研究

由一株枯草芽孢杆菌作为出发菌株,通过^60Coγ—DES（^60Coγ-硫酸二乙酯）进行物理化学复合诱变,采用平板酪蛋白水解圈法初筛,摇瓶复筛后,得到一株活力较出发菌株产酶活力增大44．5％的突变株。研究了发酵工艺参数对该突变菌体生长及产酶的影响,并确定了接种量1％,最佳初始pH为7．0,发酵温度为30℃的发酵工艺条件,结果证实,经过优化,可以获得较好的酶活,平均产酶能力可达到2135．43U,较原始菌株提高了59．60％。     

油污土壤中脂肪酶产生菌的筛选

为了获得脂肪酶产生菌的菌种,进而获得高酶活菌株.通过添加橄榄油作为唯一碳源进行富集培养,然后以透明圈平板筛选法从富油土样中筛选出能够在溴甲酚紫培养基上形成黄色透明圈的菌落,再在罗丹明B的培养基上得到高活菌种以及水解圈大小,摇瓶复筛得高活菌株,进而测定酶的活力,经筛选有10株脂肪酶产生菌酶活力较高.     

一株高产纤维素酶菌的筛选

从校园树林腐木,发霉的衣物和牛场粪便中采样,经富集培养,刚果红染色法初筛,筛选出透明圈较大的菌株6株。经过发酵产酶及酶活力测定获得高产纤维素酶野生菌株有3株,其中酶活最高的是好氧湿牛粪1菌株（HSN1）,其CMC酶活是0.230IU,FPA酶活0.154IU,它的粗酶液崩解滤纸效果十分明显。经形态学初步鉴定,该菌株应为放线菌。     

木聚糖酶产生菌的筛选

目的从土壤中筛选木聚糖酶产量高的菌株,并研究其产酶的初步条件。方法根据培养基上水解圈的大小和摇瓶培养后木聚糖酶的酶活性,筛选产酶量高的菌株。通过一系列单因素试验,研究影响产酶的碳源、氮源和无机盐。结果筛选到1株产木聚糖酶的菌株,其产酶的较优碳源、氮源和无机盐为麸皮（30g／L）、牛肉膏（10g／L）和磷酸氢二钾（1．0g／L）。结论筛选到的菌株具有生产木聚糖酶的潜力。     

额尔齐斯河野生丁(鐬)肠道产蛋白酶菌株的初步鉴定及产酶条件的研究

采用酪素培养基和脱脂乳培养基筛选额尔齐斯河野生丁(鐬)肠道内产蛋白酶菌株,共获得40株蛋白酶产生菌,其中8株蛋白水解圈较大,菌株编号为P1～P8.选取水解圈直径最大的P15为出发菌株,进行生理生化鉴定,同时摇瓶发酵探讨最佳产酶条件.结果:生理生化反应将P5初步鉴定为芽孢杆菌;蛋白酶最适产酶条件为:40℃、初始pH7.0、接种量3%、15mL/250mL的装液量、180r/min、培养时间35h,最大产酶量168.3U/L;添加微量Mg2 、Mn2 、Ca2 有稳定酶活的作用.     

一株产单宁酶酵母菌株的筛选

单宁酶全称单宁酯酰水解酶(Tannase,EC 3.11.20),能水解水解性单宁酸和没食子酸酯类中的酯键和缩酚羧键,生成没食子酸和葡萄糖。本实验从青柿、未完全成熟的香蕉、茶叶、茶园土壤等富含单宁酸的环境中取样,采用富集培养技术分离筛选出69株产单宁酶的菌株,并对其菌株的外在特性和产酶活力进行了研究和测定,最终获得一株产单宁酶活力较高的酵母菌株FC6-1。在未进行发酵条件优化前,该菌株所产单宁酶酶活达到2.86U/mL。采用薄层色谱法和SBA-40D生物传感分析仪等方法对该酶酶解产物分析,结果表明该菌株产生的单宁酶能够有效的水解单宁酸生成没食子酸和葡萄糖。     

产单宁酶菌株的筛选及选育

为得到高产单宁酶的菌株,从多年种植的茶园、柿子园以及掩埋柿子、五倍子和茶叶的花园土壤中通过平板初筛和三角瓶固体发酵复筛筛选到一株产单宁酶的曲霉菌株DNM1-39,固体培养其产单宁酶活力为1.58U/g。以DNM1-39为出发菌株,经紫外线照射、硫酸二乙酯单独处理和紫外线照射-硫酸二乙酯复合诱变处理,获得突变株UD-6,其产酶活力达2.80U/g。连续传代实验结果表明,该菌株产酶活力不变,性能稳定。     

具有胆固醇去除能力和胆盐水解酶活性的乳酸菌的体外筛选

对分离自内蒙古传统稀奶油或酸化稀奶油中的10株乳酸菌进行了胆固醇去除能力和胆盐水解酶活性的研究(定性和定量),筛选出了3株具有较高胆固醇去除能力和胆盐水解酶活力的乳酸菌菌株,分别为KLDS6.0330、KLDS6.0333和KLDS6.0335,并对它们进行16SrDNA分子生物学鉴定、酸耐受性和胆盐耐受性的测定。结果表明:这3株菌均为植物乳杆菌(L.Plantarum),并且表现出了较好的酸耐受性和胆盐耐受性。     

Comparative studies of the degradation of non-starchy polysaccharides by sorghums and barleys during malting

The β-D-glucan of whole grains of four sorghum (Sorghum bicolor (L) Moench) varieties grown in Nigeria, unlike those of barley, is not significantly reduced during malting. Pentosan level, while enhanced in barley (Hordeum rulgare L) during the same period, dropped in sorghum. Apparently sorghums have very low β-D-glucan degrading endo β 1–3,1-4 glucanase activity as observed from their failure to hydrolyse their isolated endosperm cell walls and barley β-D-glucan extracted in water at 40°C.     

两株琼胶酶高产细菌的筛选和鉴定

琼胶酶能降解琼胶多糖,生成琼胶寡糖。这些降解产物在食品等方面有良好的应用价值。本研究从江蓠中分离筛选到两株琼胶酶高产菌,编号分别是2．1-f和1.1-e,它们均为革兰氏阴性菌,呈细杆状。通过API条带分析,它们除了在对柠檬酸盐的利用上存在差别外,其它的生理生化特征完全相同,最终确定它们均为Sphingobacterium multivorum(多食鞘氨醇杆菌),其可信度分别是98．7％和99．5％。     

ISOLATION AND CHARACTERISATION OF THE AMYLOTIC SYSTEM OF SCHWANNIOMYCES CASTELLII

The amylolytic system of Schwanniomyces castellii has been isolated and purified by means of ultrafiltration followed by polyacrylamide gel electrophoresis. Both α-amylase and glucoamylase were purified. α-Amylase activity was stable from pH 5·5 to 6·5 and glucoamylase activity was stable at a more acidic range of pH 4·2 to 5·5. The optimal temperature of α-amylase activity was between 30 and 40°C with rapid deactivation at 70°C. The optimal temperature of glucoamylase was 40 to 50°C with rapid decline of activity at 60°C. The K_m of α-amylase with soluble starch as the substrate was 1·15 mg/ml and the K_m of glucoamylase with the same substrate was 10·31 mg/ml. Glucoamylase was able to hydrolyze α-1, 4 and α-1,6 glucosidic linkages, as demonstrated by its ability to hydrolyse maltose and isomaltose respectively, whereas α-amylase could hydrolyse α-1,4 glucosidic linkages only. α-Amylase was shown to be a glycoprotein, whereas no carbohydrates were associated with glucoamylase.     

Proteases of the soyabean. II. Specificity of the active fractions

Six proteolytic fractions of the soyabean differed in specificity on synthetic substrates. Their Michaelis constants on poly (L-glutamic acid) differed one from the other. The optimum pH values of proteolytic action were slightly lower than that of the crude extract. The fractions did not autolyse, nor did one fraction hydrolyse any other. Finally, none of the fractions exhibited trypsin-like activity, as characterised by ability to hydrolyse benzoylarginine ethyl ester, either at their optimum pH or at the pH optimum of trypsin.     

Lactobacilli isolated from the Armenian fermented milk product matsoun: Growth properties,antibacterial and proteolytic activity and their dependence on pH

Growth, antibacterial and proteolytic activities of two new lactobacilli strains isolated from matsoun (Armenian traditional dairy product) and their pH dependence were studied. The results demonstrated the antibacterial activity of lactobacilli against Gram‐positive and Gram‐negative test strains. This activity was stable when pH of cell culture medium was adjusted to the value of 6.5. At pH 8, the antibacterial activity of only one strain was stable. Both strains were able to hydrolyse casein in pH range of 5.5–8 with maximal activity at pH 5.5. Controlled pH conditions were suitable for biomass yield, while noncontrolled pH was better for expression of antibacterial activity.