食用菌菌种现状及退化防控措施

随着食用菌产业迅速发展，菌种在食用菌生产中的重要地位凸显。食用菌菌种质量的优劣是影响食用菌产量和品质的重要因素之一，使用劣质菌种会存在食品安全隐患，也会给食用菌生产企业带来不必要的经济损失。菌种质量参差不齐、标准缺失或难以与国际对接，严重制约着食用菌产业的持续健康发展。本文从食用菌产业现状、食用菌菌种现状及存在问题、食用菌菌种退化因素及防控、食用菌菌种质量评价等方面进行了详细论述，从多个维度分析了菌种退化原因，总结了应对菌种退化的防控措施，从本质上解决菌种退化问题，以期为食用菌规模化生产及产业发展规划提供参考。     

食用菌液体菌种的制作

在食用菌生产中,利用固体培养料培育的菌种,称为固体菌种。现在通用的斜面菌种、玻璃瓶菌种、塑料袋菌种,都是固体菌种。固体菌种的生产,不需大型复杂设备,而且方法简便,因此是食用菌菌种生产的主要方式。与固体菌种相对应的是液体菌种。将母种接种到     

辽宁省微生物科学研究院食用菌研究室简介

研究方向1．食用菌优良菌种选育2．食用菌液体菌种深层发酵技术研究3．食用菌病虫害防治技术研究主要研究内容1．杂交育种技术研究：通过食用菌孢子杂交,进行食用菌菌种选育。2．细胞融合技术研究：通过食用菌原生质体的制备融合及再生条件的研究,选育食用菌新品种。3．食用菌液体菌种深层发酵技术研究：进行食用菌液体菌种深层发酵条件及发酵工艺的研究。     

食用菌菌质分离的研究

为了防止菌种老化,寻找食用菌菌种分离的简便途径,于一九九○年六月我们对木耳、猴头、金针菇、佛罗里达平菇、香菇采取培养中诱发子实体形成原基,直接分离接种在加富PDA培养基上,获得98％的成功率,无污染,方法简便,现报如下:     

辽宁省微生物菌种保藏中心

简介辽宁省微生物菌种保藏中心是2005年经辽宁省科技厅批准、依托辽宁省微生物科学研究院组建的东北三省唯一的微生物菌种专业保藏管理机构:主要从事微生物菌种资源分离、收集、鉴定、评价,优良菌种选育、保藏、供应及对外交流开展微生物菌种保藏与应用技术研究。     

辽宁省微生物菌种保藏中心简介

辽宁省微生物菌种保藏中心于2005年由辽宁省科学技术厅批准成立,是辽宁省微生物菌种资源共享平台的依托单位。中心现有各类微生物菌种2000余株,其中所保藏的食用菌、乳酸菌、生物饲料、生物肥料等菌种在数量和种类上居省内首位。     

辽宁省微生物菌种保藏中心简介

辽宁省微生物菌种保藏中心于2005年由辽宁省科学技术厅批准成立,是辽宁省微生物菌种资源共享平台的依托单位。中心现有各类微生物菌种2000余株,其中所保藏的食用菌、乳酸菌、生物饲料、生物肥料等菌种在数量和种类上居省内首位。     

分子标记对草原野生食用菌蒙古口蘑的鉴别分析

对采自内蒙古锡林郭勒草原的野生食用菌蒙古口蘑(Tricholoma mongolicum Imai.)等10个菌种进行了ITS和ISSR分子标记的鉴定,其中蒙古口蘑共计4个不同来源菌种,其它6个菌种为子实体与蒙古口蘑形态相近的常见草原菇类或市售食用菌,鉴定结果用RAPD进行辅助分析验证。从12条ISSR引物中筛选出2条可用引物,扩增总条带数为246条,多态性标记为215个,多态性频率为87.4%。经过NT-SYS软件聚类分析,发现在ISSR分析中结合ITS方法可以有效地将蒙古口蘑与其它菌种区分开,这与RAPD法的分析结果相一致,获得了可靠的野生食用菌分子标记方法。研究表明ISSR分子标记是蒙古口蘑等野生食用菌鉴定的理想手段之一。     

平菇液体菌种的栽培试验

利用发酵法生产液体菌种,具有生产周期短,发菌速度快、出菇集中、产量高等优点。为了充分利用我所现有设备,开创食用菌工业化制种的新途径,探讨适宜的高产栽培技术措施,我们进行了平菇液体菌种的栽培试验,现将试验结果报导如下。     

辽宁省微生物科学研究院食用菌研究室简介

研究方向 1．食用菌优良菌种选育 2．食用菌液体菌种深层发酵技术研究 3．食用菌病虫害防治技术研究     

Cadmium sequestration in cells of two stains of Alcaligenes eutrophus

Abstract Alicaligenes eutrophus CH34 and its plasmid-free derivative were cultivated in the presence of cadmium. The wild type strain A. eutrophus CH34 harboured two plasmids and was cadmium-resistant, while the plasmid-free mutant AE104 was cadmium-sensitive. The Cd-resistant strain immobilized more cadmium than the Cd-sensitive one. Cadmium was mainly located in the cell envelopes of the Cd-resistant strain. Several cellular modifications were observed: thickening of the cell envelopes and changes int he peptidoglycan, i.e. its proportion in the envelopes, the ratio between glutamic acid and diaminopimelic acid, the presence of aspartic acid. These modifications should contribute to increase the cadmium sequestration capacity of the envelopes.     

一株绿僵菌的分离研究

利用马铃薯葡萄糖琼脂培养基,对一株绿僵菌进行了分离培养。对不同生长发育天数的菌落特征即颜色、大小、孢子堆的形成等特点进行了描述。在光学显微镜下观察了菌丝的形态,成熟孢子及分生孢子梗的形状、颜色及连接状况。利用扫描电镜观察了分生孢子和孢子梗的超微形态。经培养特征和形态学鉴定,确定该昆虫病原真菌是金龟子绿僵菌。     

人工栽培蛹虫草退化现象的分子分析*

利用PCR-RFLP和RAPD方法对野生驯化蛹虫草及其退化菌种进行了基因水平的分析。PCR-RFLP实验,采用真菌通用引物ITS1和ITS4,扩增出5.8S和其两端的两个转录间隔区(ITS),选用5种识别四个碱基的内切酶(HaeIII、AfaI、TagI、AluI和XspI),其中只XspI酶切结果在两个菌种中存在差异,进一步测序表明,整个片段全长534bp,共有13个位点发生碱基突变,且都为c转换为t。RAPD实验,选用4组计80个随机引物进行PCR扩增,共筛选出9个对所有供试个体均存在明显差异的引物。结果表明了退化菌株较野生驯化菌株在DNA水平上发生了频率较高的突变,这些突变可能直接与导致菌种退化的基因相关联。     

一株球孢白僵菌转基因工程菌在继代培养中的变异

基因工程是解决昆虫病原真菌致死慢、致死率低的有效途径,但在传代培养过程中,被转入的基因是否会丢失以及转基因工程株是否会像野生型菌株那样频繁地发生变异,引起产孢减少和毒力减退等生产性状的退化？针对这些问题,研究一株球孢白僵菌Beauveria bassiana转外源蝎毒基因工程菌株在继代培养过程中的的变异现象,发现工程株也和野生型菌种一样会发生菌落局变,但所插入的蝎毒基因并未丢失。与野生型出发菌株及其单孢分离株相比,工程株的角变率居高不下而产孢量及对松毛虫的毒力显著降低。然而,从该工程株筛选出的一株单孢分离     

Perceptual strain index for heat strain assessment in an experimental study: An application to construction workers

Although the physiological strain index (PhSI) is universal and comprehensive, its restrictions are recognized in terms of invasive on-site measurements and the requirement of accurate instruments. The perceptual strain index (PeSI) has been proposed as a user-friendly and practical indicator for heat strain. However, the application of this index in assessing the heat strain of construction workers has yet to be examined and documented. This study aims to ascertain the reliability and applicability of PeSI in an experimental setting that simulates a stressful working environment (i.e., environment, work uniform, and work pace) experienced by construction workers. Ten males and two females performed intermittent exercise on a treadmill while wearing a summer work uniform at 34.5 °C and 75% relative humidity in a climatic chamber. Physiological parameters (core temperature, heart rate) and perceptual variables (thermal sensation, perceived exertion) were collated synchronously at 3 min intervals. The results of two-way repeated measures analysis of variance (clothing×time) revealed that the PeSI was useful in differentiating the heat strain levels between different work uniforms. Not only did the PeSI change in the same general manner with the PhSI, but it was also powerful in reflecting different levels of physiological strain. Thus, the PeSI offers considerable promise for heat strain assessment under simulated working conditions.     

Isolation and characterization of a Lactobacillus fermentum temperate bacteriophage from Chinese yogurt

AIMS: The aim of this study was to investigate the properties of temperate bacteriophage of Lactobacillus fermentum, based on its morphology, restriction patterns, protein profile and the impact on the growth of host strain. METHODS AND RESULTS: With Mitomycin C, seven temperate phages were induced from Lactobacilli derived from Chinese yogurt. The temperate phages induced belong to the most common Bradley's group B, having hexagonal head and long, noncontractile tail. They were furthermore confirmed to be the same bacteriophage by identical restriction patterns. SDS-PAGE profile showed that the phage studied had one major structure protein about 31.9 kDa. The presence of the prophage influenced the cell shape and colony size of its lysogenic strain. CONCLUSIONS: The phage obtained had similar, but not complete identical properties with other L. fermentum phages reported. It influenced the growth behaviour of its lysogenic strain. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides some information about bacteriophages occurring in the Chinese yoghurt manufacture and contributes to our knowledge on the bacteriophage diversity in the dairy industry.     

Comparative In Vitro Development of Precocious and Normal Strains of Eimeria tenella (Coccidia)

SYNOPSIS. Eimeria tenella strain Wis-F is known to develop in chickens with a significantly shortened prepatent period and its pathogenicity is virtually completely attenuated. In vitro development of this strain paralleled development of the control (Wisconsin) strain through the first asexual generation. Instead of entering 2nd generation schizogony, however, most of the Wis-F merozoites developed into microgamonts or macrogamonts. Wall-forming bodies were prominent in developing macrogametes at 80–88 hr and began coalescing into the oocyst wall by 88 hr. Microgamete development paralleled that of macrogametes, with the appearance of multinucleate, immature forms at 72–80 hr and with recognizable, spermlike microgametes being prominent at 88–96 hr. Pathogenicity attenuation and reduction of the length of the prepatent period clearly resulted from omission of a portion of the life cycle (2nd generation schizogony).     

一株高产PLC的CW-W-90-3菌的鉴定

198 9年 ,筛选了 1株高产 phospholipaseC(PLC)的CW W 90 3菌株[1,2 ] ,据其形态特征、生理生化反应 ,初步将其归于弧菌科气单胞菌属[3 ] ,由于该菌株的许多生理生化特性与粘质沙雷氏菌相同。但其极生单鞭毛和无色素及少许生理生化特性与粘质沙雷氏菌相异。后经AutomatedBacteriaIdentificationSystem BiologMicroStationSystem检测 96种C源和N源的利用及其个体群体发育 ,说明其与粘质沙雷氏菌 (Serratiamarcescens)相符 ;并在基因组水平上研究该菌株的系统发育 ,从分子水平上对该菌株进行 16SrRNA序列分析煌同源性比较。根据CW W 90 3菌株 16SrRNA与GeneBank数据库中Serratiamarcescens的 16SrRNA的序列具有 99%的同源性 ,终将CW W 90 3菌株鉴定为粘质沙雷氏菌武汉株 (SerratiamarcescensWuhanstrain)。     

工业菌种改良述评

微生物菌种是发酵工业的基础。菌种筛选和持续不断的改良贯彻于发酵过程始终。传统的(经典的)诱变—筛选仍是目前最实用的常规技术;以基因工程为核心的现代生物技术正越来越显示出其在菌种改良上的魅力,并将最终成为微生物育种的主导技术。     

一株产海藻糖合成酶极地细菌的鉴定

从来源于极地的微生物中筛选得到一株产海藻糖合成酶的耐冷细菌S1,通过形态特征、培养特征、生理生化特征及16S rRNA基因序列分析,初步鉴定该菌为恶臭假单胞菌(Pseudomonas putida)。