海洋无脊椎动物消化酶的研究 Ⅰ、紫贻贝、日本蟳、滨螺消化酶的初步分析及其应用

本文用11种酶底物,测定了紫贻贝、日本蟳和滨螺消化系统的酶活性,并初步研究了这些消化酶的应用。实验表明:1.0％的紫贻贝消化酶在25℃、20分钟内可水解去除鲬鱼受精卵膜。1.0％的该消化酶加入等体0.5％的半纤维素酶和果胶酶,在30℃、60分钟内可制备出大量啤酒酵母原生质体。在同样条件下,1.5—2小时内,可去除大部分三角褐指藻的细胞壁。     

中国能够再造一个“大庆”

石油紧缺和价格高启迫使中国的研究机构和企业研究开发石油替代品。目前，安徽丰原集团等中国企业已基本掌握利用农作物精深加工全线替代石油产品的关键技术。     

Effect of sodium chloride and cadmium on the growth,oxidative stress and antioxidant enzyme activities of Zygosaccharomyces rouxii

Zygosaccharomyces rouxii is a salt-tolerant yeast species capable of removing cadmium(Cd) pollutant from aqueous solution. Presently, the physiological characteristics of Z. rouxii under the stress of sodium chloride(NaCl) and Cd are poorly understood. This study investigated the effects of NaCl and Cd on the growth, oxidative stress and antioxidant enzyme activities of Z. rouxii after stress treatment for 24 h. Results showed that NaCl or Cd alone negatively affected the growth of Z. rouxii, but the growth-inhibiting effect of Cd on Z. rouxii was reduced in the presence of NaCl. Flow cytometry assay showed that under Cd stress, NaCl significantly reduced the production of reactive oxygen species(ROS) and cell death of Z. rouxii compared with those in the absence of NaCl. The activities of superoxide dismutase(SOD), catalase(CAT), and peroxidase(POD) of Z. rouxii were significantly enhanced by 2%–6% NaCl, which likely contributed to the high salt tolerance of Z. rouxii. The POD activity was inhibited by 20 mg L-1Cd while the SOD and CAT activities were enhanced by 8 mg L-1 Cd and inhibited by 20 mg L-1 or 50 mg L-1 Cd. The inhibitory effect of high-level Cd on the antioxidant enzyme activities of Z. rouxii was counteracted by the combined use of NaCl, especially at 6%. This probably accounted for the decrease in Cd-induced ROS production and cell death of Z. rouxii after incubation with NaCl and Cd. Our work provided physiological clues as to the use of Z. rouxii as a biosorbent for Cd removal from seawater and liquid highly salty food.     

草鱼呼肠孤病毒096vp7基因生物信息学分析及其酵母表达载体的构建

草鱼呼肠孤病毒（Grass carp reovirus, GCRV）是草鱼出血病的病原.从患病草鱼体内分离到一株草鱼呼肠孤病毒GCRV 096,经反转录PCR,克隆得GCRV 096 长度为855 bp 的vp7 基因,并分析该基因编码蛋白的特性.结果表明,同一基因型分离株VP7 蛋白间的差异不大,但不同基因型分离株VP7 蛋白间存在很大的差异.对GCRV 096 VP7 蛋白生物信息学分析表明,信号肽位点位于20 氨基酸处,且VP7 含有4个潜在的抗原决定簇.构建GCRV 096 vp7 基因的酵母表达载体pGBKT7-S10,并成功转化至酵母中.     

Distribution and diversity of <Emphasis Type="Italic">Candida tropicalis</Emphasis> strains in different marine environments

1089 strains of yeasts were obtained from seawater,sea sediments,mud of sea saltems,guts of marine fishes,mangrove plants and marine algae.The results of routine identification and molecular analysis methods show that 44 strains among the marine yeasts obtained in this study belong to Candida tropicalis,which may indicate its wide distribution in different environment,especially in the tropical and subtropical marine environment.The wide distribution of C.tropicalis indicates that it may play an importam role in marine environment and the marine environment in turn is a good source for obtaining C.tropicalis.     

酵母培养物对凡纳滨对虾肠道菌群结构的影响

在基础饲料中分别添加质量分数0(对照)和0.30%的酵母培养物,配制2种等氮等脂饲料(分别记为Y0、Y0.3组),投喂初始体质量为(1.20±0.01)g的凡纳滨对虾(Litopenaeus vannamei)56 d。提取凡纳滨对虾肠道总DNA,采用Illumina Mi Seq高通量测序比较样品菌群组成和多样性,研究饲料中添加酵母培养物对凡纳滨对虾肠道菌群结构的影响。结果表明,Y0.3组对虾肠道分类单元(OTUs)数量、丰富度指数(Chao1、ACE值)、多样性指数(Shannon、np Shannon指数)与Y0组差异无统计学意义(P0.05);从物种分类树发现,两组的主要细菌类群均为变形菌门(Proteobacteria),其中,γ-变形菌纲是对虾肠道的最主要菌群,所占比例达69.48%;从科分类水平看,Y0.3组对虾肠道菌群链球菌科(Streptococcaceae)比Y0组提高4.98%;从优势属水平来看,Y0.3组对虾肠道的乳球菌属(Lactococcus)高于Y0组,差异有统计学意义(P0.01);Y0.3组对虾肠道的发光杆菌属(Photobacterium)低于Y0组,差异有统计学意义(P0.05)。饲料中添加质量分数0.30%酵母培养物可改善凡纳滨对虾肠道菌群多样性。     

地质新知——磨片新法

为研究矿物岩石及化石,必须磨制薄片,但因各种原料,缺乏供应,国内地质机关现尚能制片者,颇不多闻。资源委员会矿产测勘处谢家荣氏有鉴于是,特创用代用品     

一株大西洋深海酵母菌MAR-MC(3)的鉴定及生理特征分析

从大西洋中脊的深海底质中分离到一株酵母菌MAR-MC(3).该菌细胞为卵圆形,单端芽殖;在温度和NaCl浓度分别为35℃、3.4%条件下生长良好;能利用木糖、麦芽糖、半乳糖、蔗糖以及纤维二糖、阿拉伯糖、棉子糖、肌醇、木醇,但不能利用海藻糖;根据表型特征及rDNA序列分析鉴定为季也蒙毕赤酵母(Pichia guilliermondii).     

糖蜜酒精废液中钾测定方法的研究

采用四苯硼钠溶液滴定电导-测量法,对糖蜜酒精废液中钾的测定方法进行了研究。该法简便快速,测定周期仅需20m in左右,所需试剂种类和用量少,准确度和精密度与四苯硼钾重量法相当。