利用稻瘟霉分生孢子筛选有生物活性的菌株

利用稻瘟霉分生孢子筛选有生物活性的菌株杨君邵刚姚新生齐秀兰阎浩林马莉朱跃芳从广西、贵州等地土壤中分出４１７株真菌．以稻瘟霉分生孢子及菌丝生长异常或抑制为指标，从４１７株真菌中初筛出７４株活性菌株．经多次反复筛选从中得到１３株活性较好且稳定的菌株．其中...     

土壤真菌中具有引起稻瘟霉孢子形态异常活性的菌株筛选

利用稻瘟霉孢子形态异常或生长抑制活性的模型，对土壤中分出的７３２株真菌进行初步筛选，得到２４５株活性菌株，再经多次反复筛选，得到既稳定又能抑制一些病原真菌生长的１１株活性菌株，其中１３１号菌株活性最好且具有抗病原真菌作用，并具有良好的遗传稳定性。     

槲皮素对大鼠大脑皮质细胞膜α_2－肾上腺素能受体的影响

用３Ｈ－可乐定分析大鼠大脑皮质细胞膜α２－肾上腺素能受体的特征，研究槲皮素对３Ｈ－可乐定结合的影响。３Ｈ－可乐定与大鼠大脑皮质细胞膜的结合是快速（Ｋ１：０．０２７Ｌ·ｎｍｏｌ－１·ｍｉｎ－１）、可逆（Ｋ２：０．１０４ｍｉｎ－１）的，有高度亲和力（ＫＤ：５．８７±１．１３ｎｍｏｌ·Ｌ－１）和可饱和性（Ｂｍａｘ：１６０±１０ｐｍｏｌ·ｇ－１，ｐｒ）。ｌ－可乐定、ｌ－肾上腺素、ｌ－去甲肾上腺素和ｌ－异丙肾上腺素等药物抑制３Ｈ－可乐定结合的效能顺序表明，大鼠大脑皮质细胞膜上３Ｈ－可乐定结合点为α２－肾上腺素能受体。１ｎｍｏｌ·Ｌ－１～１ｍｍｏｌ·Ｌ－１槲皮素竞争抑制３Ｈ－可乐定与大鼠大脑皮质细胞膜α２－肾上腺素能受体结合，Ｋｉ值为５．７３±１．５８μｍｏｌ·Ｌ－１。     

氧代赖氨酸抗四氯化碳所致小鼠肝细胞损害的超微结构观察

小鼠ｉｇＣＣｌ４０．１％油溶液１０ｍＬ·ｋｇ－１前ｉｐ氧代赖氨酸５０ｍｇ·ｋｇ－１，每天２次，连续２ｄ，能使ＣＣｌ４所致肝细胞粗面内质网断裂减少，脂肪变性减轻，损伤恢复较快。超微结构观察提示，氧代赖氨酸能引起肝细胞胞浆局部区域溶解，基质丢失。促使ＣＣｌ３失活可能是肝细胞损伤减轻的主要原因。     

虎杖苷对CCl_4损伤原代培养大鼠肝细胞的保护作用

目的研究虎杖苷（ＰＤ）对ＣＣｌ４损伤原代培养大鼠肝细胞的保护作用。方法原位灌流法分离大鼠肝细胞，培养２４ｈ后加入ＰＤ，同时造成ＣＣｌ４损伤，分别于损伤后６，１２，２４和４８ｈ测培养液中谷丙转氨酶（ＡＬＴ）、丙二醛（ＭＤＡ）和还原型谷胱甘肽（ＧＳＨ）活性，４８ｈ后用ＭＴＴ比色法测肝细胞存活率。结果ＰＤ１×１０－７～１×１０－４ｍｏｌ·Ｌ－１能不同程度地抑制ＡＬＴ和ＭＤＡ的上升，提高ＧＳＨ水平，显著提高细胞存活率，以１×１０－５ｍｏｌ·Ｌ－１效果最好。结论ＰＤ１×１０－７～１×１０－４ｍｏｌ·Ｌ－１能有效保护ＣＣｌ４造成的原代培养大鼠肝细胞损伤     

硫酸沙丁胺醇缓释胶囊药代动力学和生物利用度研究

以英国 Ｇｌａｘｏ Ｐｈａｒｍａｃｅｕｔｉｃａｌｓ生产的沙丁胺醇控释片（Ｖｏｌｍａｘ, ８ ｍｇ）为参比制剂,采用随机分组交叉试验设计方法,考察 ２０名健康男性志愿受试者单剂量和多剂量口服成都地奥公司生产的硫酸沙丁胺醇缓释胶囊（Ｓａｌｂｕｔａ, ８ ｍｇ）后的药代动力学和相对生物利用度,ＨＰＬＣ－紫外检测器测定血浆中沙丁胺醇的浓度。用３Ｐ８７药动学程序对结果进行处理。单剂量给药时,Ｓａｌｂｕｔａ和Ｖｏｌｍａｘ分别在５５０±０．８５ｈ和５．３０±０.９５ ｈ达到峰浓度１０.６１±３.９４ｎｇ·ｍＬ-１和１０．５２±２．５９ ｎｇ·ｍＬ-１,血药浓度曲线下面积分别为 １２４.７４±３３.８６ｈ·ｎｇ．ｍＬ－１和 １２６.０２±３８．１７ｈ·ｎｇ·ｍＬ－１,Ｓａｌｂｕｔａ的相对生物利用度为９８.９８±１２.０４％。多剂量给药达稳态时,Ｃ分别为１２.９４±３.３５ｎｇ·ｍＬ－１和１２.６±３.３６ｎｇ·ｍＬ．Ｃ　分别为５.８４±１.３４ ｎｇ·ｍＬ－１和６.１６±１.３３ｎｇ·ｍＬ-１,平均稳态血药浓度 Ｃａｖ分别为 ８.７２±２．１７ ｎｇ·ｍＬ-１和 ８．６７±２．１６ ｎｇ·ｍＬ-１,波动度 ＤＦ分别为 ８１.８２±１７.７４％和７６.０３±２０.４８％     

前胡丙素对培养心肌细胞~（45）Ca~（2＋）摄入及细胞内游离钙的影响

利用培养的乳鼠心肌细胞测定细胞４５Ｃａ２＋的摄入及细胞内游离钙的浓度。结果表明，前胡丙素（Ｐｒａ－Ｃ）１０－１００μｍｏｌ·Ｌ－１依浓度抑制４５Ｃａ２＿的摄入，并抑制由３０μｍｏｌ·Ｌ－１ＫＣｌ所引起的４５Ｃｓ２＋摄入的增加，同时Ｐｒａ－Ｃ１００μｍｏｌ·Ｌ－１对去甲肾上腺素所诱发的４５Ｃａ２＿摄入的增加也有抑制作用。Ｐｒａ－Ｃ１０μｍｏｌ·Ｌ－１和维拉帕米１０μｍｏｌ·Ｌ－１能抑制细胞外高钾（３０，５０ｍｍｏｌ·Ｌ－１）引起的［Ｃａ２＋］ｉ的升高，同时Ｐｒａ－Ｃ３０ｍｏｌ·Ｌ－１和维拉帕米１０μｍｏｌ·Ｌ－１对去甲肾上腺素１０μｍｏｌ·Ｌ－１在无钙及含ＣａＣｌ２１．３ｍｍｏｌ·Ｌ－１的溶液中所引起的［Ｃａ２＋］，的增加也有抑制作用。提示前胡丙素对心肌细胞的作用与其阻滞钙通道有关。     

氢氯噻嗪对大鼠主动脉收缩及^86Rb外流的影响

氢氯噻嗪（ＨＣＴ）０．１，０．３ｍｍｏｌ·Ｌ＾－１可抑制低浓度ＫＣＬ（〈４０ｍｍｏｌ·Ｌ＾－１），ＮＥ和５－ＨＴ所致大鼠主动脉条收缩，对高Ｋ＾＋（８０ｍｍｏｌ·Ｌ＾－１）去极化时ＣａＣｌ２所致收缩无影响。ＨＣＴ对低浓度ＫＣＬ所致收缩的抑制作用可被ＢａＣｌ２和ＴＥＡ拮抗，不被Ｇｌｉ拮抗。ＨＣＴ３ｍｍｏｌ·Ｌ＾－１可使＾８６Ｒｂ外流增加，此作用可这ＢａＣｌ２拮抗，不被Ｇｌｉ拮抗。ＨＣＴ抑制大鼠主动脉…     

地塞米松对豚鼠离体气管平滑肌收缩功能的影响

在体外研究了地塞米松（Ｄｅｘ）对豚鼠离体气管平滑肌收缩的影响。ＣａＣｌ２和组胺（Ｈｉｓ）引起了气管条明显的收缩，ｐＤ２分别为３．９及５．９２。用地塞米松温育后，氯化钙和组胺的量效曲线均明显降低，ｐＤ＇２分别为４．７４和６．６７。Ｄｅｘ对Ａｃｈ３×１０－６ｍｍｏｌ·Ｌ－１和前列腺素Ｆ２α３ｍｍｏｌ·Ｌ－１引起的支气管平滑肌收缩也有逆转作用，ＩＣ５０分别为２．４１×１０－５ｍｏｌ·Ｌ－１和４．２６×１０－４ｍｏｌ·Ｌ－１，提示Ｄｅｘ有明显的支气管扩张作用。     

L-赖氨酸高产菌株筛选

本实验以Ｌ－赖氨酸产生菌钝齿棒杆菌（Ｃｏｒｙｎｅｂａｃｔｅｒｉｕｍｃｒｅｎａｔｕｍ）ＯＭ－４（ＨＳ＋，ＡＥＳｒ，Ｍｅｔｒ）为出发菌株，经硫酸二乙酯和氯化锂复合诱变处理，用ＡＥＣ（Ｓ－［２－氨乙基）－Ｌ－半胱氨酸）和苏氨酸定向筛选获得了高抗ＡＥＣ的突变株ＡＴ－５（ＨＳ＋，ＡＥＣｒ，Ｍｅｔｒ）菌株，再以ＡＴ－５为出发菌株经亚硝基胍诱变处理，获得一株产Ｌ－赖氨酸的ＴＡ（２－噻唑－ＤＬ－丙氨酸）抗性突变株（ＡＴＴ一６８号），菌株产酸量由原来ＯＭ一４菌株的４６．３ｍｇ／ｍＬ提高到７４．８ｍｇ／ｍＬ提高１６１．５％，在筛选结构类似物抗性突变株时采用小钢杯法，可大大节省结构类似物药品．     

利用生物模型-稻瘟霉筛选活性菌株

目的从土壤真菌中筛选有抗真菌、抗肿瘤活性的菌株。方法以稻瘟霉分生孢子以及菌丝形态变化为指标 ,并通过稳定性考查 ,进行活性筛选。结果从云南、江西等地土壤中分离出 737株真菌 ,对其中的 14 2株活性菌株进行多次反复筛选 ,从中得到 6株活性、批次稳定性和遗传稳定性良好的菌株。进行温度稳定性考查的过程中发现多色青霉、黑粘座曲霉、产紫青霉三株菌发酵液活性基本不受温度影响。结论稻瘟霉是良好的筛选抗真菌、抗肿瘤活性菌株的初筛模型     

土壤丝状真菌AF-5、SQ_2-17菌株的筛选及其抗菌活性的研究

从辽宁、山东等省采得的 45份土样进行了菌种分离及纯化 ,共获得 482株丝状真菌 ,利用以稻瘟霉分生孢子形态异常作为生物活性筛选模型 ,对其进行了初筛 ,初步得到 2 42株活性菌株 ,经多次复筛获得了既对稻瘟霉菌株有较强活性又能抑制一些病原真菌生长的 16株活性菌株。其中AF 5、SQ2 17菌株能使稻瘟霉孢子高度变形 ,同时又具有较强的抗病原真菌作用及良好的遗传稳定性。     

红树林放线菌抗沃柑病原真菌的研究

摘要：目的 分离鉴定沃柑叶斑病害中的病原真菌,并从广西红树林来源放线菌中筛选高效抑制病原真菌的菌株,为开展沃柑真菌病害的防治奠定基础。方法 采用组织分离法对病原真菌进行分离和纯化培养,通过形态学、ITS基因序列分析及构建系统发育树相结合的方法对病原真菌进行鉴定,并按照柯赫氏法则对健康沃柑叶片进行回接验证。采用平板对峙法对24株红树林放线菌进行抑菌活性初筛,并检测活性菌株发酵产物的抗菌活性及防病害效果。通过antiSMASH对目标菌株的基因组序列进行分析,预测其合成次级代谢产物的能力。结果 从沃柑叶斑病害中分离出4种植物病原真菌,其中大豆茎点霉(Boeremia exigua)和腐皮镰刀菌(Fusarium solani)可导致沃柑叶片出现叶斑病症;从24株放线菌中筛选到1株链霉菌M2020,其对4种病原真菌C1~C4表现出很好的抑菌活性,且其发酵产物在沃柑真菌病害(真菌C4侵染)防治试验中效果显著;菌株M2020基因组中含有38个负责聚酮类、非核糖体多肽类和萜烯类等次级代谢产物生物合成的基因簇。结论 致使沃柑出现叶斑病症的病原真菌至少有大豆茎点霉和腐皮镰刀菌,链霉菌M2020具有防治沃柑叶斑病害的潜力。     

珊瑚共附生真菌次级代谢产物研究进展

近年来,珊瑚共附生真菌化学成分研究受到越来越多的关注,截至2014年底,已经从38种珊瑚中分离共附生真菌95种,涉及44个属,从中分离得到化合物200余个,这些化合物表现出抗肿瘤、抗真菌、抗炎和抗污等生物活性。珊瑚共附生真菌来源的新化合物数量呈逐年上升趋势,仅4年时间就发现化合物近百个,这些化合物显示出不同的生物活性。从化学结构和生物活性两个方面综述近4年对珊瑚共附生真菌次级代谢产物的研究进展,以期为进一步的深入研究提供参考。     

New dithiolopyrrolone antibiotics from Saccharothrix sp. SA 233. I. Taxonomy,fermentation, isolation and biological activities

Three new natural antibacterial and antifungal dithiolopyrrolone antibiotics were isolated along with the known iso-butyropyrrothine and thiolutine from the fermentation broth of an actinomycete strain which was isolated from a saharian palm grove soil collected at Adrar, south Algeria. The strain was identified as Saccharothrix sp. The three new antibiotics exhibited broad antimicrobial activity against gram-positive bacteria, yeasts and fungi in vitro.     

Survey of antimicrobial streptomycetes from soils of West Bengal: characterization and identification of potent broad spectrum antibiotic producing Streptomyces albidoflavus 321.2

Survey of 611 streptomycetes isolates from 330 soil samples from various parts of West Bengal were done for their antimicrobial activity against Gram positive, Gram negative bacteria, unicellular and filamentous fungi. The strain 321.2 showed inhibition against all the test organisms used and found as potent. The morphological, cultural, physiological and biochemical characters were studied, compared with known species and identified as Streptomyces albidoflavus. This strain produces an antibiotic.     

A new diimide derivative from the co-culture broth of two mangrove fungi (strain no. E33 and K38)

A new diimide derivative, named ( ? )-byssochlamic acid bisdiimide (1), was isolated from the mixed broth of two mangrove fungi (strain no. K38 and E33) from the South China sea coast. The structure of 1 was determined by comprehensive spectroscopic methods, including 1D and 2D NMR (COSY, HMQC, and HMBC) and semi-synthesis. Primary bioassays showed that 1 had weak cytotoxic activity against Hep-2 and HepG2 cells.     

Ecology and Population Biology of Aflatoxigenic Fungi in Soil

Soil serves as a reservoir for Aspergillus flavus and A. parasiticus, fungi that produce carcinogenic aflatoxins in agricultural commodities. Populations in soil are genetically diverse and individual genotypes show a clustered distribution pattern within fields. Surveys over large geographic regions suggest that climate and crop composition influence species density and aflatoxin‐producing potential. Aflatoxigenic fungi reside in soil as conidia, sclerotia and hyphae, which act as primary inocula for directly infecting peanuts or for infecting aerial crops (corn, cottonseed, tree nuts) through wind and insect dispersal. Infected crops periodically replenish soil populations during drought years.     

Valinomycin affects the morphology of Candida albicans

Microbial metabolites were screened for inhibitors of hyphal growth in Candida albicans. Inhibitory activity was found among metabolites of a culture of an actinomycete, which had been isolated from soil. The active substance inhibited hyphal growth and induced growth as a chain of yeast cells under hyphal growth induction conditions. The active substance was purified and analyzed with 1H-NMR, 13C-NMR and mass spectra. The substance was identified as valinomycin, and commercial valinomycin inhibited hyphal growth as effectively as the purified metabolite. The effective concentration was from 0.49 to 62.5 microg/ml. Valinomycin also inhibited hyphal growth in other dimorphic fungi, Candida tropicalis and Aureobasidium pullulans. These results suggest that valinomycin may be a useful tool for understanding the morphological transition of dimorphic fungi.     

A bioencapsulation and drying method increases shelf life and efficacy of Metarhizium brunneum conidia

This study reports the development of encapsulated and dried entomopathogenic fungus Metarhiuzm brunneum with reduced conidia content, increased conidiation, a high drying survival and enhanced shelf life. Dried beads prepared with the fillers corn starch, potato starch, carboxymethylcellulose or autoclaved baker’s yeast, showed enhanced survival with increasing filler content. The maximum survival of 82% was found for beads with 20% corn starch at <0.1 water activity. While increasing starch content inhibits the conidiation, autoclaved baker’s yeast and a combination with starch enhanced the conidiation to 1.0?×?10⁸ conidia/bead. Beads with conidia content reduced to 0.01% multiplied conidia in a “microfermentation” by the factor 1000. A bioassay confirmed that conidia formed from rehydrated beads were virulent against Tenebrior molitor larvae. After six months of storage, encapsulated conidia showed improved shelf life compared to non-formulated conidia. This “microfermenter” will pave the way for encapsulated fungi to be used as cost-effective biocontrol agents.