Plant cell and tissue culture: alternatives for metabolite production

Plant cell culture systems represent a potential renewable source of valuable medicinals, flavours, essences and colourants that cannot be produced by microbial cells or chemical syntheses. However, only a few cultures produce these compounds in commercially useful amounts. The low productivities are associated with our poor understanding of the biochemistry of these systems. Recent advances in molecular biology, enzymology, physiology and fermentation technology of plant cell cultures suggest that these systems will become a viable source of important natural products. This review examines the sate of the art of production of medicinal plant secondary metabolites by plant cell cultures.     

Species identification in the genus Saprolegnia (Oomycetes): Defining DNA-based molecular operational taxonomic units

The lack of a robust taxonomy in the genus Saprolegnia is leading to the presence of incorrectly named isolates in culture collections and of an increasing number of misassigned sequences in DNA databases. Accurate species delimitation is critical for most biological disciplines. A recently proposed approach to solve species delimitation (taxonomic diagnosis system) of difficult organisms is the definition of molecular operational taxonomic units (MOTUs). We have used 961 sequences of nrDNA ITS from culture collections (461 sequences) and GenBank (500 sequences), to perform phylogenetic and clustering optimization analyses. As result, we have identified 29 DNA-based MOTUs in agreement with phylogenetic studies. The resulting molecular clusters support the validity of 18 species of Saprolegnia and identify 11 potential new ones. We have also listed a number of incorrectly named isolates in culture collections, misassigned species names to GenBank sequences, and reference sequences for the species. We conclude that GenBank represents the main source of errors for identifying Saprolegnia species since it possesses sequences with misassigned names and also sequencing errors. The presented taxonomic diagnosis system might help setting the basis for a suitable identification of species in this economically important genus.     

Citrate, a specific substrate for the isolation of Clostridium sphenoides.

With a medium containing citrate as the carbon and energy source, 10 clostridial strains were isolated from various mud samples. Characterization of these strains revealed that they all belonged to the same species, Clostridium sphenoides. Strains of this organism obtained from culture collections were also able to grow citrate, whereas 15 other clostridial species tested were not. Citrate was fermented by C. sphenoides to acetate, ethanol, carbon dioxide, and hydrogen. Experiments with stereospecifically 14C-labeled citrate indicated that citrate lyase was involved in citrate degradation.     

Developmental Nutrition of Nematodes: the Biochemical Role of Sterols,Heme Compounds,and Lysosomal Enzymes

Attempts to develop defined in vitro culture systems for the growth, reproduction and development of free-living nematodes have yielded much basic information about their nutritional requirements and biochemistry. Requirements for sterol and heme have been identified suggesting that some nematodes lack de novo synthesis of these molecules. Possible pathways of metabolism of these nutritional requirements can be derived from in vitro experiments that use a variety of sterol and heine sources as supplements to the culture mediuin. These pathways are reviewed as well as the possible role of sterol and heme in the biology of free-living and parasitic nematodes, Since these molecules must be acquired dietarily, the possible involvement of lysosomal enzymes in digestion is discussed. Also considered is the possibility that lysosomal enzymes change when nematodes are fed on a heine protein source.     

Culture collections — their services to biotechnology

The need to recruit qualified and experienced employees is a major concern of many organizations engaged in biotechnology. Universities and industry are scoured to find the right people, but where are we to find promising new candidates for the most numerous, and arguably most talented section of the biotechnological workforce — microorganisms and other types of cells? The international network of culture collections offers the best answer, and a proper understanding of their roles and capabilities can save biotechnologists an immense amount of time and money.Among the millions of microbial, plant and animal cells stored in the world's culture collections it is often possible to find one that exactly suits a biotechnologist's particular requirements or one that can be developed to perform a specific task. This article outlines the services offered by culture collections, generally using the UK collections as examples of the main activities throughout the world.     

Bioreactor cultivation of Escherichia coli for production of recombinant penicillin G amidase from Alcaligenes faecalis

The penicillin G amidase (PGA) from Alcaligenes faecalis, which has interesting properties for use in combinatorial biochemistry, was produced by recombinant expression in Escherichia coli. The corresponding gene was cloned into a multicopy vector under the strict regulatory control of the rhamnose inducible promoter. Cells were grown in a synthetic minimal medium in a bioreactor (5 l working vol.), and production of PGA was induced by repeated addition of the inducer rhamnose, that served also as a carbon source. The fermentation yield was about 4500 units PGA activity per liter of culture medium.     

微藻种质资源库——藻类科学研究和产业发展的重要平台

微藻是指一类形态微小, 能够进行光合作用, 以单细胞或简单多细胞形式存在的藻类。作为一类重要的生物资源, 活体微藻的保藏和共享服务是开展藻类科学研究和藻类产业发展的必要平台和基础。坐落于中国科学院水生生物研究所的淡水藻种库(FACHB-Collection)正式成立于1973年, 1996年作为创会成员加入中国科学院典型培养物保藏委员会; 2019年成为国家水生生物种质资源库的核心成员。该库保藏逾3400株微藻, 隶属于9门169属。年均为国内外用户提供2500株藻株, 并提供藻种鉴定、分离纯化和培养技术等方面的服务和咨询。文章回顾了国际微藻种质资源库的发展历史和现状, 介绍了国内微藻种质资源保藏情况, 着重介绍国家水生生物种质资源库——淡水藻种库在库藏藻株多样性、共享服务、藻株无菌化、超低温保藏技术及优良品种选育与应用等方面的进展, 瞄准提升我国在藻类学研究和藻类产业研发的竞争力, 提出了藻种资源库未来发展的建议。     

Application of good laboratory practice (GLP) to culture collections of microbial and cell cultures

Although the principles and the necessity for good laboratory practice (GLP) guidelines to confirm the credibility, integrity, and quality of non-clinical laboratory studies have been known for more than a decade, culture collection activities are not subject to them. Because of recent advances in biotechnology, culture collections face increased demands not only for quality cultures but also current information. When applied in culture collections, GLP guidelines prove to be an excellent management tool as well as a cost-effective system of providing authentic and reliable microbial and cell cultures and associated data.     

Yeast culture collections of the world: meeting the needs of industrial researchers

The importance of selecting optimal yeast strains for research or industrial applications is often underestimated. For example, utilizing a strain background that already provides the desired stress tolerance or nutrient utilization profile can eliminate costly strain optimization. Yeast culture collections can provide not only the yeast strains but also data and curator expertise to help narrow the search for the optimal strain. While some collections are known for a broad range of cultures and services, other "boutique" collections can provide a broader selection of strains of certain categories, a surprising amount of characterization data, and assistance in selecting strains. This article provides information on dozens of yeast collections of the world, profiles of selected yeast culture collections, and the services that they provide: e.g., strain preservation for patent or safe deposit purposes, species identification service, training workshops, and consulting on yeast identification and physiology. Utilization of these services can save industrial researchers valuable time and resources.     

The Fungal Genetics Stock Center in the context of a world wide community of ex situ fungal germplasm repositories

Most fungal biology researchers depend on culture collections, or more aptly, ex situ fungal germplasm repositories, either for the materials upon which they work, or as a long-term home for their materials after their projects are finished. These collections are broadly distributed and typically supported by the local government. The large number of collections, notwithstanding, some collections have greater impact than others. This review will discuss the fungal germplasm repositories around the world with special attention paid to the Fungal Genetics Stock Center. To facilitate their activities collections have joined together in networks, both locally and internationally. Additional information on public policy and how it impacts collections will be presented and the impact of collections will be highlighted.     

一株瘤胃源乳酸利用菌的分离鉴定及其体外代谢特性

【目的】从饲喂高精料的本地山羊瘤胃内分离到一株利用乳酸并能产生大量丙酸的菌株L9,并进一步研究了该菌在调控瘤胃微生物发酵中的作用。【方法】采用厌氧培养技术,结合形态、生理生化特性和16SrRNA基因序列分析结果。【结果】该菌株被鉴定为反刍兽新月形单胞菌（Selenomonas ruminantium）。该菌株体外代谢特性研究表明,L9可利用乳酸作为唯一碳源,该菌在24h内可对90mmol／L的乳酸完全降解。体外摸拟瘤胃急性酸中毒的发酵试验结果表明,以淀粉为底物时,与对照组相比,添加菌株L9可显著降低瘤胃微生物体外培养体系中乳酸浓度,提高pH值,提高总挥发性脂肪酸和丙酸浓度,并显著降低乙酸与丙酸的浓度比（P〈0．05）。【结论】结果显示,菌株L9是一株可代谢乳酸,促进丙酸生成,提高总挥发性脂肪酸浓度的有益瘤胃细菌。     

Structuring strain data for storage and retrieval of information on fungi and yeasts in MINE, the Microbial Information Network Europe

A distributed Microbial Information Network Europe (MINE) is being constructed by a number of major microbial culture collections in countries of the European Community, with the support of the Biotechnology Action Programme (BAP) of the Commission of the European Community. The representatives of the collections participating in MINE have agreed to adopt a general format for the computer storage and retrieval of strain data. This uniform format will facilitate the electronic combination and exchange of data from different collections in order to produce integrated catalogues and the use of identical commands to search the different databases. It is recommended to other collections who may wish to contribute data to the MINE network or between themselves. Three kinds of records can be linked to the leading 'species records': strain records, synonym records, and alternative morphonym records. A minimum data set of 30 fields (similar to the fields used for producing catalogues) is defined that facilitates the exchange of data between the national nodes and serves as a directory to strains available at other nodes. It is suggested that the full strain record comprise 99 fields, grouped in 12 blocks: internal administration--name--strain administration--status--environment and history--biological interactions--sexuality--properties (cytology, biomolecular data)--genotype and genetics--growth conditions--chemistry and enzymes--practical applications. Several fields are divided into subfields of different ranks. Delimiters are used either to separate a range of entries that have to be indexed or to divide an entry from the reference to its source or remarks that should not be indexed. The contents and structure of the fields proposed for filamentous fungi and yeasts are described and in some cases illustrated by examples. Uniformity of input is essential for indexed fields and desirable for non-indexed fields. Seven thesaurus files are envisaged to ensure consistency.     

A review of the volatile metabolites of fungi found on wood substrates

The holdings of eight collections of fungi have been examined for organisms isolated from wood and/or trees. Further selection of these fungi has been made according to their reported ability to produce volatile, biologically active metabolites. It is emphasized that the isolates in the collections do not necessarily produce such metabolites. The list of fungi fulfilling these conditions is slightly augmented by reports we have found in the literature, where the fungi concerned have not yet been deposited. The biochemistry of these compounds is considered with particular emphasis on their biosynthesis including that by Homo sapiens. The physiological and toxicological activity of these metabolites is reviewed especially with reference to their potential role in the complex symbioses existent in, for example, a tree. The review concludes with a discussion of areas of botany deserving increased attention in the hope that this will stimulate further work. The statements in the review are based on 173 references.     

Biodiversity amongst microorganisms and its relevance

Concluding remarks from the joint IUBS/IUMS workshop on Biodiversity amongst microorganisms and its relevance held in Amsterdam on 7–8 September 1991. An international microbial ecology programme can be justified in its own right now that appropriate investigative tools have been developed. Microorganisms influence global change, and indicate global health and environmental quality. At the same time, an inventory of the world's microbial species and their properties is required, together with associated culture collections and genomes. Sampling methods need to be standardized, both for species and functions. Extreme environments are a particularly rich source of microbial genomes, and endangered habitats should be sampled as a matter of priority. Cataloguing and conserving the world's microbial biodiversity is justifiable and scientifically important.     

Towards a unified data infrastructure to support European and global microbiome research: a call to action

High-quality microbiome research relies on the integrity, management and quality of supporting data. Currently biobanks and culture collections have different formats and approaches to data management. This necessitates a standard data format to underpin research, particularly in line with the FAIR data standards of findability, accessibility, interoperability and reusability. We address the importance of a unified, coordinated approach that ensures compatibility of data between that needed by biobanks and culture collections, but also to ensure linkage between bioinformatic databases and the wider research community.     

铁尾矿区油松根际溶磷泛菌D2的筛选鉴定及溶磷特性

从河北省迁安市马兰庄镇铁尾矿植被恢复区油松根际分离出2株溶磷细菌,经过平板初筛和摇瓶复筛得到1株溶磷能力较强的菌株D2.通过菌落形态、生理生化特性及16S rDNA序列分析,确定此菌株D2属于泛菌属.利用液体发酵试验测定不同碳源、氮源对菌株D2溶磷能力的影响,通过高效液相色谱测定D2在不同氮源条件下产生有机酸的种类和浓度.结果表明:菌株D2对磷酸三钙有较强的溶磷能力,培养液有效磷含量最高为392.13 mg·L^-1,菌株D2的溶磷能力在碳源为葡萄糖、氮源为硫酸铵时效果最好;高效液相色谱测定发现,不同氮源条件下,D2分泌有机酸的种类和浓度存在差异,以硫酸铵、氯化铵、硝酸钾、硝酸钠、硝酸铵为氮源,均产生草酸、甲酸、乙酸和柠檬酸,以硫酸铵、氯化铵、硝酸铵为氮源还产生苹果酸.相关性分析表明,乙酸含量与有效磷含量间呈显著正相关(r=0.886,P<0.05),表明溶磷泛菌D2分泌的乙酸对无机磷的溶解有明显的促进作用,这也很可能是该菌株的重要溶磷机制之一.     

一株[艹屈]高效降解菌的分离鉴定及其降解特性

以多环芳烃[艹屈] (Chrysene)为选择培养基的碳源, 从焦化污泥中筛选出一株[艹屈]的高效降解菌SQ-1, SQ-1可在以[艹屈]为唯一碳源的无机盐培养基中生长, 经过电镜形态学观察、生理生化和16S rDNA序列分析, 并基于16S rDNA序列结果, 构建了该菌株的系统发育树。最终确定菌株SQ-1为木糖氧化无色杆菌(Achromobacter xylosoxidans)。又考察了[艹屈]的初始浓度、投菌量、pH值对SQ-1菌株降解[艹屈]效果的影响, 确定了最佳降解条件。结果表明, 该菌对水中[艹屈]具有良好的降解特性, 在[艹屈]浓度为40 mg/L、接种量10% (V/V)、pH 7.0~7.5、温度30°C条件下, 接种5 d后对[艹屈]的降解效率达到80%以上。     

Synthesis and accumulation of poly(3-hydroxybutyric acid) by Rhizobium sp

Forty-two Rhizobium strains obtained from different culture collections were evaluated quantitatively for poly(3-hydroxy-butyric acid) [PHB] production in shake flask culture. The majority of the strains produced the maximum amount of PHB during the late exponential or stationary phase of growth. Synthesis and accumulation of PHB in different species of Rhizobium were found to vary between 1-38% of their dry biomass. Growth and PHB production by the Rhizobium strain TAL-640 were greatly influenced by the C-source and D-mannitol was fundamental to both processes. The identity and purity of PHB isolated from TAL-640 have also been confirmed by UV-, IR- and 1H-NMR spectroscopic analyses.