南极罗斯海可培养微生物多样性和功能研究及一株南极细菌新种的鉴定
发布时间：2018-11-15 11:51
【摘要】：南极地区极端的气候条件使其成为地球上最严酷的陆地生境之一,其特殊生境条件孕育了独特的微生物类群。南极区域少有人类活动,其深海沉积物不仅地质学特征复杂,所含矿物成分种类众多,是复杂的微生物栖息地,也是一种特殊的生态环境。罗斯海(Ross Sea)是南太平洋深入南极洲的大海湾,位于罗斯陆缘冰(Ross ice shelf)之北,维多利亚地阿代尔角西(Cape Adare)与爱德华七世半岛的科尔贝克角东(Cape Colbeck)之间(158°W-170°E)。本论文对南极罗斯海沉积物中可培养微生物的多样性和低温酶活性进行了研究,并采用遗传学、表型特征、生理生化指标和化学分类指标等多项分类法鉴定出1株南极细菌新种。利用传统平板培养法,对采集自罗斯海的6份沉积物样品进行了细菌和真菌的分离培养,选择形态差异较大的细菌和真菌进行了 16S rDNA和ITS鉴定。16S rDNA序列分析结果显示需盐杆菌属7株,芽孢杆菌属7株,海洋杆菌属4株,动球菌属6株,嗜冷杆菌属12株。ITS鉴定结果表明筛选得到的真菌属于6个属:枝孢属、链格孢属、弯孢属,蜡蚧菌属、定殖真菌属、青霉菌属,其优势真菌为枝孢属菌株。以上菌株中,88.89%的细菌可产生α-葡萄糖苷酶,72.22%的细菌可以产生蛋白酶,83.33%的细菌可产生脲酶,69.44%的细菌可产生β-半乳糖苷酶,69.44%的细菌能将硝酸盐还原成亚硝酸盐和氮气;产淀粉酶、纤维素酶和酪蛋白酶的真菌分别占真菌菌株总数的37.93%、34.48%、61.54%;8株菌株对至少一种受试菌株有拮抗作用,且其拮抗活性主要针对真菌(辣椒疫霉)和革兰氏阴性细菌(大肠杆菌、鳗弧菌),未发现对革兰氏阳性细菌(枯草杆菌)有明显抑制作用的菌株。由以上结果可以看出,罗斯海沉积物中的微生物具有丰富的多样性,这为筛选具有特殊功能的菌株和发现新菌种提供了基础。利用传统平板培养法,以海水R2A培养基,对一株南极细菌2PM7进行分类鉴定。结果显示,该细菌是革兰氏阴性菌,严格需氧,呈杆状,无鞭毛,无运动性;在0-20℃条件下生长状况良好,该菌株适合生长的pH值为4.0-8.0,适合在低于0.9%(w/v)NaCl的培养基中生长;具有氧化酶、过氧化氢酶活性。该菌DNA的G+C含量为44.4mol%,细胞呼吸醌为甲基萘醌7(MK-7),主要脂肪酸为 iso-C_15:0(18.1%)、C16:1ω5c(14.2%)和 Summed feature3(40.5%)。2PM7与粘液杆菌属(Mucilaginibacter)的一株细菌标准菌株Mucilaginbacterr rugui sp.nov.的相似度为96.8%,另外与该科其他细菌的同源相似性均低于96.8%。构建的系统进化树显示,2PM7形成了一个独立的分支。因此,根据该菌在遗传学特征和表型特征上所表现出来的特殊性,认定该菌属于黏液杆菌属的一个新种,命名为Mucilaginibact ning sp.nov.。
[Abstract]:The extreme climatic conditions in the Antarctic region make it one of the harshest terrestrial habitats on the earth, and its special habitat conditions give birth to unique microbial groups. There are few human activities in the Antarctic region. The deep-sea sediments not only have complex geological characteristics, but also contain many kinds of mineral elements. They are complex microbial habitats and a special ecological environment. The Ross Sea (Ross Sea) is the great bay of the South Pacific deep into Antarctica, north of Ross' continental edge ice (Ross ice shelf). Between Cape Adele West (Cape Adare), Victoria, and Cape Colbeck East (Cape Colbeck), Edward VII (158 掳W-170 掳E).) The diversity and low temperature enzyme activity of culturable microorganisms in the sediments of the Ross Sea, Antarctica, were studied in this paper, and the genetic and phenotypic characteristics were used. A new Antarctic bacterial species was identified by several taxonomic methods, such as physiological and biochemical indexes and chemical taxonomic indexes. The isolation and culture of bacteria and fungi from six sediment samples from the Ross Sea were carried out by using the traditional plate culture method. 16s rDNA and ITS were used to identify bacteria and fungi with different morphology. The results of 16s rDNA sequence analysis showed that 7 strains of Salina, 7 strains of Bacillus, 4 strains of Marine Bacillus, 6 strains of Acinetococcus. The results of ITS identification showed that the selected fungi belong to 6 genera: Schizosporium, Alternaria, Curvularia, scale, colonizing fungi, Penicillium, and its dominant fungi are Schizosporium. Of the above strains, 88.89% produced 伪 -glucosidase, 72.22% produced protease, 83.33% produced urease, 69.44% produced 尾 -galactosidase. 69.44% bacteria can reduce nitrate to nitrite and nitrogen. The fungi producing amylase, cellulase and caseinase accounted for 37.93% of the total number of fungal strains, respectively. 8 strains had antagonistic effects on at least one of the tested strains, and their antagonistic activities were mainly directed against fungi (Phytophthora capsici) and Gram-negative bacteria (E. coli, Vibrio anguilli). No significant inhibition of gram-positive bacteria (Bacillus subtilis) was found. It can be seen from the above results that the microbes in the sediments of the Ross Sea are rich in diversity, which provides a basis for the screening of strains with special functions and the discovery of new strains. A Antarctic bacterial strain 2PM7 was classified and identified on seawater R2A medium by traditional plate culture method. The results showed that the bacteria was Gram-negative, strictly aerobic, rod-like, without flagella and motility. The strain was in good condition at 0-20 鈩，
本文编号：2333232
[Abstract]:The extreme climatic conditions in the Antarctic region make it one of the harshest terrestrial habitats on the earth, and its special habitat conditions give birth to unique microbial groups. There are few human activities in the Antarctic region. The deep-sea sediments not only have complex geological characteristics, but also contain many kinds of mineral elements. They are complex microbial habitats and a special ecological environment. The Ross Sea (Ross Sea) is the great bay of the South Pacific deep into Antarctica, north of Ross' continental edge ice (Ross ice shelf). Between Cape Adele West (Cape Adare), Victoria, and Cape Colbeck East (Cape Colbeck), Edward VII (158 掳W-170 掳E).) The diversity and low temperature enzyme activity of culturable microorganisms in the sediments of the Ross Sea, Antarctica, were studied in this paper, and the genetic and phenotypic characteristics were used. A new Antarctic bacterial species was identified by several taxonomic methods, such as physiological and biochemical indexes and chemical taxonomic indexes. The isolation and culture of bacteria and fungi from six sediment samples from the Ross Sea were carried out by using the traditional plate culture method. 16s rDNA and ITS were used to identify bacteria and fungi with different morphology. The results of 16s rDNA sequence analysis showed that 7 strains of Salina, 7 strains of Bacillus, 4 strains of Marine Bacillus, 6 strains of Acinetococcus. The results of ITS identification showed that the selected fungi belong to 6 genera: Schizosporium, Alternaria, Curvularia, scale, colonizing fungi, Penicillium, and its dominant fungi are Schizosporium. Of the above strains, 88.89% produced 伪 -glucosidase, 72.22% produced protease, 83.33% produced urease, 69.44% produced 尾 -galactosidase. 69.44% bacteria can reduce nitrate to nitrite and nitrogen. The fungi producing amylase, cellulase and caseinase accounted for 37.93% of the total number of fungal strains, respectively. 8 strains had antagonistic effects on at least one of the tested strains, and their antagonistic activities were mainly directed against fungi (Phytophthora capsici) and Gram-negative bacteria (E. coli, Vibrio anguilli). No significant inhibition of gram-positive bacteria (Bacillus subtilis) was found. It can be seen from the above results that the microbes in the sediments of the Ross Sea are rich in diversity, which provides a basis for the screening of strains with special functions and the discovery of new strains. A Antarctic bacterial strain 2PM7 was classified and identified on seawater R2A medium by traditional plate culture method. The results showed that the bacteria was Gram-negative, strictly aerobic, rod-like, without flagella and motility. The strain was in good condition at 0-20 鈩，
本文编号：2333232
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