南極羅斯�？膳囵B(yǎng)微生物多樣性和功能研究及一株南極細(xì)菌新種的鑒定
發(fā)布時(shí)間：2018-11-15 11:51
【摘要】：南極地區(qū)極端的氣候條件使其成為地球上最嚴(yán)酷的陸地生境之一,其特殊生境條件孕育了獨(dú)特的微生物類群。南極區(qū)域少有人類活動(dòng),其深海沉積物不僅地質(zhì)學(xué)特征復(fù)雜,所含礦物成分種類眾多,是復(fù)雜的微生物棲息地,也是一種特殊的生態(tài)環(huán)境。羅斯海(Ross Sea)是南太平洋深入南極洲的大海灣,位于羅斯陸緣冰(Ross ice shelf)之北,維多利亞地阿代爾角西(Cape Adare)與愛德華七世半島的科爾貝克角東(Cape Colbeck)之間(158°W-170°E)。本論文對(duì)南極羅斯海沉積物中可培養(yǎng)微生物的多樣性和低溫酶活性進(jìn)行了研究,并采用遺傳學(xué)、表型特征、生理生化指標(biāo)和化學(xué)分類指標(biāo)等多項(xiàng)分類法鑒定出1株南極細(xì)菌新種。利用傳統(tǒng)平板培養(yǎng)法,對(duì)采集自羅斯海的6份沉積物樣品進(jìn)行了細(xì)菌和真菌的分離培養(yǎng),選擇形態(tài)差異較大的細(xì)菌和真菌進(jìn)行了 16S rDNA和ITS鑒定。16S rDNA序列分析結(jié)果顯示需鹽桿菌屬7株,芽孢桿菌屬7株,海洋桿菌屬4株,動(dòng)球菌屬6株,嗜冷桿菌屬12株。ITS鑒定結(jié)果表明篩選得到的真菌屬于6個(gè)屬:枝孢屬、鏈格孢屬、彎孢屬,蠟蚧菌屬、定殖真菌屬、青霉菌屬,其優(yōu)勢真菌為枝孢屬菌株。以上菌株中,88.89%的細(xì)菌可產(chǎn)生α-葡萄糖苷酶,72.22%的細(xì)菌可以產(chǎn)生蛋白酶,83.33%的細(xì)菌可產(chǎn)生脲酶,69.44%的細(xì)菌可產(chǎn)生β-半乳糖苷酶,69.44%的細(xì)菌能將硝酸鹽還原成亞硝酸鹽和氮?dú)?產(chǎn)淀粉酶、纖維素酶和酪蛋白酶的真菌分別占真菌菌株總數(shù)的37.93%、34.48%、61.54%;8株菌株對(duì)至少一種受試菌株有拮抗作用,且其拮抗活性主要針對(duì)真菌(辣椒疫霉)和革蘭氏陰性細(xì)菌(大腸桿菌、鰻弧菌),未發(fā)現(xiàn)對(duì)革蘭氏陽性細(xì)菌(枯草桿菌)有明顯抑制作用的菌株。由以上結(jié)果可以看出,羅斯海沉積物中的微生物具有豐富的多樣性,這為篩選具有特殊功能的菌株和發(fā)現(xiàn)新菌種提供了基礎(chǔ)。利用傳統(tǒng)平板培養(yǎng)法,以海水R2A培養(yǎng)基,對(duì)一株南極細(xì)菌2PM7進(jìn)行分類鑒定。結(jié)果顯示,該細(xì)菌是革蘭氏陰性菌,嚴(yán)格需氧,呈桿狀,無鞭毛,無運(yùn)動(dòng)性;在0-20℃條件下生長狀況良好,該菌株適合生長的pH值為4.0-8.0,適合在低于0.9%(w/v)NaCl的培養(yǎng)基中生長;具有氧化酶、過氧化氫酶活性。該菌DNA的G+C含量為44.4mol%,細(xì)胞呼吸醌為甲基萘醌7(MK-7),主要脂肪酸為 iso-C_15:0(18.1%)、C16:1ω5c(14.2%)和 Summed feature3(40.5%)。2PM7與粘液桿菌屬(Mucilaginibacter)的一株細(xì)菌標(biāo)準(zhǔn)菌株Mucilaginbacterr rugui sp.nov.的相似度為96.8%,另外與該科其他細(xì)菌的同源相似性均低于96.8%。構(gòu)建的系統(tǒng)進(jìn)化樹顯示,2PM7形成了一個(gè)獨(dú)立的分支。因此,根據(jù)該菌在遺傳學(xué)特征和表型特征上所表現(xiàn)出來的特殊性,認(rèn)定該菌屬于黏液桿菌屬的一個(gè)新種,命名為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 擄W-170 擄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 偽 -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，
本文編號(hào)：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 擄W-170 擄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 偽 -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，
本文編號(hào)：2333232
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