从新疆吉木乃地区冬季泌乳双峰驼中培养的细菌多样性及产酸、产酶活效果

Diversity of culturable bacteria in lactating Bactrian camels in Jimunai area of Xinjiang during winter and the acid-and enzyme-producing activities

摘要:

[目的]本研究拟通过可培养获得驼源细菌,分析菌种分布规律,获得产酸、产酶特性的菌株资源,为驼源益生细菌的开发和利用提供资源和技术支撑。[方法]采用稀释法筛选新疆吉木乃地区冬季养殖双峰泌乳骆驼驼乳、唾液及直肠粪便中的细菌,通过16S rRNA基因序列分析对菌株进行鉴定;透明圈法对产酸和产酶的菌株进行初筛,并对菌株产有机酸能力及产淀粉酶、纤维素酶和蛋白酶活力进行复筛。[结果]共培养出63株细菌菌株,经分子鉴定得知,从驼粪中分离的35株菌以嗜冷杆菌属和不动杆菌属为主;驼乳中分离出的21株菌以假单胞菌属和明串珠菌属为优势菌属;唾液中分离纯化出7株,主要为芽孢杆菌属;平板初筛得到产酸菌共有11株,1株粪源肠膜明串珠菌(Leuconostoc mesenteroides) 2F11M乳酸产量最高,达到3.93 mg/mL;1株奶源乳酸明串珠菌(Leuconostoc lactis) 2N5M乙酸产量最高,达到12.73 mg/mL;1株粪源蒙氏肠球菌(Enterococcus mundtii) 2F17M丙酸产量最高,达到10.36 mg/mL;根据初筛产透明圈,产酶菌株主要分离自驼粪和驼奶,其中产淀粉酶的菌株17株,产纤维素酶的菌株10株,产蛋白酶的菌株15株;1株奶源的贝莱斯芽孢杆菌(Bacillus velezensis) Nai1的淀粉酶活性最高,为509.07 μg/(min·mL),1株粪源鲁氏不动杆菌(Acinetobacter lwoffii) 2F5N的纤维素酶活性最高,为156.87 μg/(min·mL),1株奶源枯草芽孢杆菌(Bacillus subtilis) 2N2N产蛋白酶活性最高,为3.59 μmol/(min·mL)。[结论]从新疆泌乳双峰骆驼中筛选出了多种产酸、产酶菌株,且活力都较好,具有制备微生态制剂的潜力。

Abstract:

[Objective] Culturable bacteria were isolated from camel and the distribution of bacteria was analyzed.On this basis,the acid-producing and enzyme-producing bacteria were screened out.This study is expected to provide resource and technical support for the development and utilization of camel-derived probiotics.[Methods] Serial dilution-coating method was used to screen bacteria in milk,saliva,and rectal feces of lactating Bactrian camels in Jimunai area of Xinjiang in winter,and the strains were identified by 16S rRNA gene sequencing.Strains producing acid and enzyme were identified with the transparent circle method,and the ability of producing organic acid,amylase,cellulase,and protease was further evaluated.[Results]A total of 63 bacterial strains were cultured,with 35 strains from camel feces (mainly Psychrobacter and Acinetobacter),21 from camel milk (dominated by Pseudomonas and Leuconostoc),and 7 from saliva (mainly Bacillus).A total of 11 acid-producing strains were screened out,with the feces-derived Leuconostoc mesenteroides 2F11M yielding the most lactic acid (up to 3.93 mg/mL),milk-derived L.lactis 2N5M achieving the highest acetic acid yield (12.73 mg/mL),and the feces-derived Enterococcus Mundtii 2F17M topping the bacteria in propionic acid yield (10.36 mg/mL).According to the transparent circle,the enzyme-producing strains were mainly from camel feces and camel milk.Among them,17,10,and 15 strains produced amylase,cellulase,and proteinase,respectively.The milk-derived Bacillus velezensis Nai1 had the highest amylase activity (509.07 μg/min/mL) and feces-derived Acinetobacter lwoffii 2F5N had the highest cellulase activity (156.87 μg/min/mL).In addition,milk-derived B.subtilis 2N2N achieved the highest protease activity (3.59 μmol/min/mL).[Conclusion] A variety of acid-producing and enzyme-producing strains with high activities were screened from lactating Bactrian camels in Xinjiang,which have the potential for the preparation of microecologics.