海洋源芽孢杆菌的分离鉴定及其消化酶代谢产物的测定

【目的】从海洋生物和环境中分离鉴定出产消化酶代谢产物的芽孢杆菌,为微生态制剂的研制提供益生菌种。【方法】从雷州半岛近岸海域采集样品,用高温处理、富集培养和分离培养的方法获得分离菌株;通过菌落形态、细胞结构、染色特征、生化试验和16S rRNA基因测序对分离菌株进行鉴定;采用福林-酚比色法、淀粉-碘比色法和橄榄油乳化法测定分离菌株代谢产物中的蛋白酶、淀粉酶和脂肪酶活性。【结果】从22份样品中初步鉴定出疑似芽孢杆菌43株,筛选3种消化酶综合活性最强的8株,经生化试验和16S rRNA基因测序鉴定,有蜡样芽孢杆菌3株、暹罗芽孢杆菌3株、特基拉芽孢杆菌1株、解木糖赖氨酸芽孢杆菌1株。其中,解木糖赖氨酸芽孢杆菌BC1产脂肪酶活力最高,为52.13 U/mL;蜡样芽孢杆菌BC3产蛋白酶活力最高,为4.78U/mL;暹罗芽孢杆菌BC6产淀粉酶活力最高,为2.35 U/mL。【结论】成功筛选出产消化酶代谢产物的海洋源芽孢杆菌。     

不同成熟度雪茄烟晾制过程碳水化合物及相关酶活性变化规律研究

为了解不同成熟度晾制对雪茄烟叶品质的影响,以雪茄烟品种‘H382’为研究对象,采用大田试验方法,研究不同成熟度雪茄烟在晾制过程中碳水化合物含量及相关酶活性的变化,并对不同成熟度雪茄烟进行品质分析。结果表明,在晾制过程中适熟采收的烟叶失水速度和含水率适中,能促进内在物质的转化;雪茄烟适熟时采收,淀粉含量最低,淀粉降解速率快、降解较彻底,总糖、还原糖含量相对较高;淀粉酶和淀粉磷酸化酶活性均以适熟采收的烟叶最高;晾制后烟叶化学成分的主成分综合得分也以适熟采收的烟叶最高,化学品质较好。研究可为五指山雪茄烟叶采收提供理论基础。     

许氏平鮋消化道中部分消化酶的研究

对许氏平 (Sebastesschlegeli)消化道内的 5种与消化吸收有关的酶进行分布和活性测定。结果表明 ,(1)肠道各段均具很高碱性磷酸酶活性 ,最适 pH为 9.7。食道和胃几乎没有碱性磷酸酶活性。 (2 )消化道各部位均含酸性磷酸酶 ,肠道活性最高 ,自幽门盲囊起依次递降。食道和胃酸性磷酸酶活性明显低于肠 ,胃和肠酸性磷酸酶的最适 pH均为 5 .3。 (3)肠道中羧酸酯酶活性明显高于胃 ,且 2者羧酸酯酶最适 pH差别较大 ,分别为 8.4和 6 .8。(4)胃蛋白酶活性明显高于肠道 ,胃蛋白酶最适pH为 2 .6 ,肠蛋白酶最适 pH为 9.4。 (5 )胃淀粉酶活性明显低于肠道 ,胃淀粉酶最适 pH为 4 .6 ,肠道淀粉酶最适pH为 7.0。这表明许氏平对蛋白质的初步消化在胃中进行 ,在肠中进一步消化和吸收 ,而对糖类和脂类的消化和吸收主要在肠道进行     

Effect of incubation temperature on carbohydrate digestion in important teleosts for aquaculture

The activity and capacity (activity × tissue weight) of digestive carbohydrases (total carbohydrase, α‐glucosidase, α‐amylase) was examined in vitro under a range of (more realistic) incubation temperatures (5, 18 and 25°C) and pH (7.6) more likely to be encountered during rearing, along the digestive tract of important teleost species for aquaculture (Dicentrarchus labrax, Sparus aurata, Oreochromis aureus, Oncorhynchus mykiss and Salmo salar). Results indicate, among other things, an overestimation of digestive carbohydrase levels when performing assays at 37°C, a different effect of temperature on digestive enzyme performance along the digestive tract of examined species, and the increased importance of α‐glucosidase towards carbohydrate digestion. Implications regarding the capacity of each species for carbohydrate digestion in nature, as well as feed manufacturing, are discussed.     

Development of Digestive Enzymes in California Halibut <Emphasis Type="Italic">Paralichthys californicus</Emphasis> Larvae

California halibut Paralichthys californicus is an important commercial species with high aquaculture potential in Baja California Sur, México. To optimize the feeding process using live prey and/or inert diets, we evaluated alkaline proteases, pepsin, trypsin, chymotrypsin, leucine aminopeptidase, lipase, α-amylase, and acid and alkaline phosphatase activities on starved larvae and larvae fed live prey. Highest activities were observed for alkaline protease, trypsin, chymotrypsin, leucine aminopeptidase, and alkaline phosphatase in feeding larvae than starved larvae on day 4 after hatching. At day 5, a sizeable increase in all enzymatic activities was detected in feeding larvae. Alkaline protease, trypsin, chymotrypsin, and alkaline phosphatase decreases progressively from day 5 until day 18. At day 18, a slight pepsin activity was observed. This was considered an indicator of the start of digestive system maturation. We concluded that total enzymatic equipment for this species is complete between day 18 and 30 after hatching. Based on this evidence, early weaning from live prey to inert feed would be possible at this time.     

天山一号冰川产淀粉酶酵母菌的筛选及其系统发育分析

[目的]筛选并分析天山一号冰川冰层产淀粉酶的低温酵母菌。[方法]对天山一号冰川冰层含冰冻土产低温淀粉酶的低温酵母菌菌株进行筛选、纯化,并对其生理多样性和系统发育多样性进行研究。[结果]从天山一号冰川冰层含冰冻土中分离出60株酵母菌,并从中筛选出6株产低温淀粉酶的菌株,根据细胞菌落形态、菌体特征和26S rDNA D1/D2区域序列系统发育分析,6株菌分别隶属于红酵母属(Rhodotorula)、隐球菌属(Cryptococcus)和掷孢酵母属(Sporobolomyces),最适生长温度为20~24℃,为兼性耐冷细菌。[结论]研究可为了解冰川酵母菌的系统发育多样性以及低温淀粉酶的生物技术研发奠定基础。     

Serum amylase and isoamylase values in dogs with pancreatic disease

Serum amylase and isoamylase values were determined in three groups of dogs. The first group contained control dogs while the other groups contained dogs with confirmed exocrine pancreatic insufficiency and diabetes mellitus respectively. The trypsin-like immunoreactivity test was also carried out on sera from dogs with exocrine pancreatic disease (EPI). A significant difference was detected in the serum amylase values between the three groups which may be of limited diagnostic value. Dogs with EPI had values lower than normal while those with diabetes mellitus had values higher than control dogs. No evidence of exocrine pancreatic insufficiency was found in dogs with diabetes mellitus.     

酶法提取芦笋皮中高活性膳食纤维的研究

以芦笋皮为原料，采用酶法水解制备高活性膳食纤维。试验结果表明：用0.54%的脂肪酶(100 U/mg)、0.80%的淀粉酶(25 U/mg)和0.80%的糖化酶(20 U/mg)、1.20%的蛋白酶(100 U/mg)可提取出高活性的膳食纤维。所得膳食纤维纯度高，总膳食纤维含量达83.08%，其中水溶性膳食纤维17.02%，不溶性膳食纤维66.06%。而且生理活性好，持水性和溶胀性分别为886%和4.5 mL/g。     

皱马鞍菌液体培养过程中胞外酶及还原糖的动态变化

对皱马鞍菌(Helvella crispa)液体培养过程中不同胞外酶活性和还原糖含量的动态变化进行了研 究。结果表明,在28 ℃、110 r,／min恒温振荡培养条件下,皱马鞍菌菌丝体生物量在第13天达峰值(9．40 g／L);发酵 液pH值逐渐上升,从第9天(8．24)后基本保持平稳;胞外蛋白含量于第6天达峰值(8．30 mg／mL);胞外还原糖 含量急剧上升,至第3天达峰值(20．43 mg／mL),之后迅速下降,到第8天降为1．38 mg／mL,此后一直维持在1 mg／mL水平。皱马鞍菌对碳水化合物的利用顺序为淀粉、纤维素、木质素。淀粉酶的活性高峰出现在第3天,并一 直保持在较高水平;CMC酶6 d后急剧分泌,第7天达峰值,之后又急速下降;愈创木酚氧化酶和多酚氧化酶活性 高峰出现最晚,均在第14天。酸性蔗糖转化酶活性在培养期间始终很低,而中性蔗糖转化酶活性呈阶梯上升趋势。