Cultivation of the two perennial brown algae Ecklonia cava and E. stolonifera for abalone feeds in Korea

Ecklonia cava and Ecklonia stolonifera are perennial brown algae that form sea forests off the coast of Korea. Both species are cultured to supply a summer feed for the abalone industry. Recent expansion of the abalone industry in Korea has been bringing an increase in demand for fresh algal supply. Zoospores of the two algae were seeded in October 2006 on seed frames coiled with 100 m of seed fibers. After 2 months of indoor culture and 2 months of intermediate culture, growth and production of the two algae were compared during their main cultivation period from March 2007 to June 2008, in the culture ground in Wando, Korea (34°26′18.68″ N, 127°05′43.88″ E), in situ. Growth rate of E. cava and E. stolonifera was 1.058 and 3.089 mm day^?1, respectively. The mean production of E. stolonifera obtained from the culture ropes was ca. 12 kg wet wt. m^?1 of culture rope while production of E. cava was ca. 3 kg wet wt. m^?1 of culture rope. The difference in production was attributed from the different growth strategies of the two algae, with only E. stolonifera being able to regenerate blades from the holdfast. The ability to regenerate blades from the holdfast therefore makes E. stolonifera the preferred species for biomass production for abalone feeds. In a 120-day feeding experiment, growth rate, weight gain, and survival rate of abalone showed that E. cava and E. stolonifera feeds could provide an alternative feed to Saccharina japonica during summer months.     

Genome-wide analysis of Nilaparvata lugens nymphal responses to high-density and low-quality rice hosts

The brown planthopper （BPH） Nilaparvata lugens is an economically impor- tant pest on rice plants. In this study, the higher population density and yellow-ripe stage of rice plants were used to construct adverse survival conditions （ASC） against BPH nymphs. Simultaneously, the low population density and tillering stage of rice plants were used to establish a suitable survival condition （SSC） as a control. Solexa/Illumina sequencing was used to identify genes of BPH nymphs responding to ASC. Significantly longer duration development of BPH nymphs and significantly lower brachypterous ratio of BPH adults were observed by ASC compared with SSC. A total of 2 544 differentially expressed genes （DEGs） were obtained and analyzed by BLASTx, Gene Ontology and KEGG Orthology. Gene ontology analysis revealed that the DEGs were mainly involved in categories of cell, cell part, cellular process, binding, catalytic, organelle and metabolic processes. 1138 DEGs having enzyme commission numbers were assigned to different metabolic pathways. The largest clusters were neurodegenerative diseases （137, 12.0%）, followed by carbohy- drate metabolism （113, 9.9%）, amino acid metabolism （94, 8.3%）, nucleotide metabolism （76, 6.7%）, energy metabolism （64, 5.6%）, translation （60, 5.3%）, lipid metabolism （58, 5.1%）, and folding, sorting and degradation （52, 4.6%）. Expressing profile of 11 DEGs during eight nymphal developmental stages of BPH were analyzed by quantitative real- time polymerase chain reaction. The 11 genes exhibited differential expression between ASC and SSC during at least one developmental stage. The DEGs identified in this study provide molecular proof of how BPH reconfigures its gene expression profile to adapt to overcrowding and low-quality hosts.     

香菇多糖对微生态失调小鼠肠道菌群及免疫功能的调节作用

目的 探讨香菇多糖对微生态失调小鼠肠道菌群及免疫功能的调节作用.方法 经盐酸林可霉素灌胃建立肠道微生态失调小鼠模型,香菇多糖灌胃治疗,同时设正常对照组、自然恢复组和丽珠肠乐组.7d后处死各组小鼠,进行肠道菌群定量、免疫器官体重及其淋巴细胞转化率检测.结果 用香菇多糖对肠道微生态失调小鼠进行治疗后,小鼠肠道双歧杆菌、乳酸杆菌数量显著增加,而肠杆菌和肠球菌的数量显著降低;脾脏指数明显增加,对胸腺指数无影响;显著增强了淋巴细胞转化率.结论 盐酸林克霉素灌胃能诱导微生态失调小鼠模型的有效建立.香菇多糖能调整小鼠肠道菌群及免疫功能.     

食用菌加工产业研究现状与前景

食用菌加工是利用物理、化学和生物方法处理食用菌子实体或菌丝体,生产食用菌制品。它可以解决食用菌从生产到商品出售所存在的时间矛盾,提高食用菌的商品价值。详细介绍了食用菌的干制加工、盐渍加工及罐藏加工技术,概括了食用菌深加工产业的发展现状及研究进展,提出了对食用菌加工的展望。     

酒精发酵过程中酿酒酵母耐受环境胁迫的研究进展

提高酿酒酵母细胞耐受环境胁迫（高渗透压、高浓度酒精和高温）的能力对酒精工业生产具有重要的意义。对提高酿酒酵母耐受性的研究方法和策略的发展历程进行了综述。基因组学、转录组学和蛋白质组学等现代组学技术在这一领域的研究获得了广泛的应用。这些技术将提供期待的信息,去理性改造并获得更加耐受胁迫的工业酵母菌株。     

植物叶绿体分裂的分子机制

叶绿体是植物细胞内一种重要的细胞器．它不仅是光合作用的场所,还是其它多种中间代谢的场所．叶绿体起源于蓝细菌,与其原核祖先类似,通过二分裂方式进行增殖．最近的研究表明,叶绿体的分裂装置包含原核起源和真核起源的蛋白质,它们在叶绿体的内膜内侧和外膜外侧协同作用以完成叶绿体的分裂．在过去十几年里,包括丝状温度敏感蛋白Z（FtsZ）、Min系统蛋白、质体分裂蛋白（PDV）和ARC蛋白等在内的多个叶绿体分裂相关组分被分离鉴定．本文简要介绍了叶绿体分裂装置各成员的发现、叶绿体被膜的收缩和叶绿体分裂位点的选择机制．另外,植物发育过程中叶绿体分裂可能受到细胞的控制,但目前对细胞如何调控叶绿体分裂知之甚少．本文对该领域的最新研究进展也进行了综述．