【摘 要】
：
Marine microorganisms were considered to be important sources of marine bioactive compounds. The major objective of the study was to isolate and characterize bacteria with antimicrobial activities from the various marine environment of Egypt. In this resp
【机 构】
：
Department of Botany and Microbiology,Faculty of Science,Al-Azhar University,Cairo 11884,Egypt;The R
论文部分内容阅读
Marine microorganisms were considered to be important sources of marine bioactive compounds. The major objective of the study was to isolate and characterize bacteria with antimicrobial activities from the various marine environment of Egypt. In this respect, thirty-five bacterial isolates were recovered from sediment samples collected from different spots along the Egyptian Red Sea coastline and Alexandria coastline during the summer season of 2017 and 2018. According to the morphological, physiological, and biochemical characteristics, the bacterial isolates were clustered into 13 groups designated as A, B, ···, M. And, 14 Gram-negative and 21 Gram- positive bacteria were determined. The isolated bacterial strains were screened for their potentiality for antimicrobial agent(s) production against ten indicator strains. Strain Mo13 was showed high antimicrobial activity against all empirical strains. Subsequently, the most promising marine bacterial isolate with code MO13 was identified as Bacillus zhangzhouensis OMER4 according to the phenotypic characterization through morphological, physiological, and biochemical tests as well as genotypic characterization through the 16S rDNA technique. The bioactive components were extracted with ethyl acetate, then analyzed using GC-MS and the substantial component was recognized as phenol, 2, 4-bis(1, 1-dimethyl ethyl).
其他文献
为了快速并有效地计算海洋平台等薄壁箱型梁结构的约束扭转极限承载能力,进行了薄壁梁约束扭转极限承载能力简化计算方法研究.基于塑性极限状态分析理论,提出了薄壁梁约束扭转极限状态应力分布假设,将薄壁梁视作为一系列由主要支撑构件和扶强材支撑的板格,推导了薄壁梁约束扭转极限承载能力上限的计算公式.应用非线性有限元方法验证了所提假设和计算公式的精度,将所提方法应用于箱型梁模型和半潜平台的约束扭转极限承载能力的计算分析,并与非线性有限元结果进行了比对,结果表明,本方法具有较高的精度,可用于海洋平台等薄壁梁的扭转极限承载
针对海相软土地区螺旋钢管桩承载力低与腐蚀问题,提出一种新型压力注浆螺旋钢管桩,并设计5根足尺试验桩,进行现场抗拔承载性能试验,研究螺旋叶片直径与排布方式对成桩直径与桩基抗拔承载性能的影响.结果表明,成桩直径与螺旋叶片直径呈正相关,在每节延长段钢管末端设置螺旋叶片利于提高水泥土柱完整性,使成桩直径更为饱满,提高桩基的抗拔承载性能.将试验结果和现行规范抗拔极限承载力计算结果进行对比,计算结果约为实测平均值的94％,在此基础上提出压力注浆螺旋钢管桩抗拔承载力计算参数修正建议,为后续的设计提供参考.
海上浮式风力机受风、浪、流等外部载荷影响,运营期间经常处于偏航工况,给风力机基础运动响应和锚泊载荷带来重要影响.基于经典叶素动量理论及势流理论,建立海上浮式风力机水—气动力耦合分析模型,对在非定常风、不规则波浪联合作用下,风力机偏航时基础运动响应及锚泊载荷等进行分析.研究发现,额定风速工况下,风力机偏航对平台纵荡和纵摇运动影响较大,偏航30°时纵荡和纵摇平均值比偏航0°时分别下降20.68％和37.36％,垂荡运动响应受风力机偏航影响较小;锚泊载荷变化趋势与平台运动及锚链布置有关,平台纵荡对锚泊载荷影响较
The majority of fishery stocks in the world are data limited, which limits formal stock assessments. Identifying the impacts of input data on stock assessment is critical for improving stock assessment and developing precautionary management strategies. W
In contrast to typical planktonic hydromedusae, Cladonema medusae are mostly benthic, with specialised adhesive branches to adhere to the substrate. In this study, a Cladonema species discovered in a laboratory aquarium in Fuzhou, China, was confirmed as
The size-spectrum model has been considered a useful tool for understanding the structures of marine ecosystems and examining management implications for fisheries. Based on Chinese tuna longline observer data from the central and eastern tropical Pacific
The identity of Rostraria bierii, originally described as a larval amphinomid from Cape Setozaki, Pacific coast of Japan, is investigated. Based on the original description and illustrations, reinterpretations conclude the “larva” to represent a partial j
In the western and central Pacific Ocean, upper strata waters exhibit highly dynamic oceanographic features under ENSO variability. This has been proved to be responsible for the dynamic change of both abundance and zonal distribution of skipjack tuna (Ka
Long-term variations in population structure, growth, mortality, length at median sexual maturity, and exploitation rate of threadfin bream (Nemipterus virgatus) are reported based on bottom trawl survey data collected during 1960–2012 in the Beibu Gulf,
Antitumor activity is one characteristic function of some certain antimicrobial peptides (AMPs) found in recent years. In the present study, we attempted to detect potential anticancer activity of a recombinant piscidin 5-like from Larimichthys crocea (rL