PCR-RFLP Analysis of the Internal Transcribed Spacer (ITS) Region for Identification of 3 Clam Species

ABSTRACT Restriction site analysis of the internal transcribed spacer (ITS) region amplified by the polymerase chain reaction (PCR) was used for the specific identification of 3 clam species: Ruditapes decussatus (grooved carpet shell), Venerupis pullastra (pullet carpet shell), and Ruditapes philippinarum (Japanese carpet shell). PCR amplification using primers based on nucleotide sequences of Mytilus ITS regions produced a fragment of 1195 bp in R. decussatus, 1074 bp in V. pullastra, and 1188 bp inR. philippinarum. Digestion of the PCR products with endonucleases HinfI and Rsa I, followed by agarose gel electrophoresis of the digested products, yielded specific restriction profiles that enabled direct visual identification of the species analyzed.     

漳州市夏秋季主要贝类中副溶血性弧菌分布情况分析

调查漳州市售主要贝类中副溶血性弧菌的带菌状况,为消费者提供食品安全风险参考。从漳州市区的8大市场无菌采集花蛤、文蛤和蛏的新鲜样品;用硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂培养基(Thiosulfate citrate bile salts sucrose agar culture medium,TCBS)分离纯化疑似菌落,聚合酶链式反应(Polymerase Chain Reaction,PCR)扩增不耐热溶血素基因(thermolabile hemolysin,tlh)的特异片段;并对分子检测阳性的菌株进行生化鉴定。结果表明,采集到53份花蛤、50份文蛤和42份蛏的样品,经过TCBS筛选分别得到37株、45株和36株疑似菌落,分离率分别为69.8%、90.0%和85.7%;PCR确定副溶血性弧菌阳性率分别为35.8%(19/53)、30.0%(15/50)和54.8%(23/42);革兰氏染色和主要生化实验确定疑似菌均为副溶血性弧菌,符合率达100%。漳州市所售水产品受副溶血性弧菌污染较为严重,市民食用需严格无害化处理,避免不同种类水产品间的交叉污染。      

Biogas production performance of Undaria pinnatifida using a bio-based pH buffer—Shell of Venerupis species (Asari)

Biogasification is the suitable biomass-to-biofuel technology in rural areas. In coastal communities, seaweed is an abundant feedstock for household biogas digester. However, biogasification requires expensive and dangerous chemicals for pH adjustment. Hence, Venerupis species shell was tested as pH buffer on biogasification of Undaria pinnatifida. Addition of 3% and 5% (w/w) shell at the start of digestion successfully started biogasification [86.4 ml CH₄/g volatile solid (VS) and 109.5 ml CH₄/g VS, respectively]. Biogasification efficiencies of shell setups (3% shell: 24.2%, 5% shell: 30.7%, and “BH then 5% shell”: 19.4%) were lower than in “BH then NaOH” (68.3%). Nonetheless, biogas start-up failed when shells are not added.     

Genetic differentiation between the clam species Ruditapes decussatus (grooved carpet shell) and Venerupis pullastra (pullet carpet shell) by PCR–SSCP analysis

Genetic differentiation of the clam species Ruditapes decussatus (grooved carpet shell) and Venerupis pullastra (pullet carpet shell) has been achieved based on polymerase chain reaction–single‐strand conformation polymorphism (PCR–SSCP) analysis. A short fragment (150 bp) of the α‐actin gene was amplified by PCR. Amplicons were denatured to obtain single‐stranded DNA, electrophoresed on a non‐denaturing polyacrylamide gel and visualised by silver staining for detection of SSCPs. Species‐specific DNA band patterns were obtained for R decussatus and V pullastra, allowing clear differentiation of the two clam species. © 2002 Society of Chemical Industry