Microbial community analysis of mesophilic anaerobic protein degradation process using bovine serum albumin (BSA)-fed continuous cultivation
Microbial community analysis of mesophilic anaerobic protein degradation process using bovine serum albumin (BSA)-fed continuous cultivation
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DOI：
10.1263/jbb.99.150
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发表时间：
2005-02-01
影响因子：
2.8
通讯作者：
Kida, K
中科院分区：
文献类型：
--
作者：
Tang, YQ;Shigematsu, T;Kida, K
以牛血清白蛋白（BSA）为唯一碳源和能源，研究了两种中温厌氧恒化器（恒化器1和恒化器2）对蛋白质的降解能力、微生物群落结构以及添加微量金属元素的影响。恒化器1的主要产物为挥发性脂肪酸和氨，恒化器2的主要产物为甲烷、CO2和氨，临界稀释率分别为0.15 d（-1）和0.08 d（-1）。荧光原位杂交（FISH）与古细菌和细菌结构域特异性探针表明，古细菌细胞是非常有限的恒化器I，而大的几种类型的古细菌细胞的群体存在于恒化器2。系统发育分析的基础上16 S rRNA基因克隆序列，DGGE，和定量实时聚合酶链反应（PCR）表明，在该域的degreea，产甲烷菌隶属于属Methanosaeta和Methanoculleus占主导地位的恒化器2。在细菌领域内，从恒化器I获得的rRNA基因隶属于三个门：厚壁菌门（43%）、拟杆菌门（50%）和变形菌门（7%）。从恒化器2获得的rRNA基因中，共有56%属于三个门，厚壁菌门（32%），拟杆菌门（11%）和变形菌门（13%），而44%的rRNA基因仍然未分类。在这两个恒化器中获得了系统发育上不同的克隆，这表明不同的蛋白质降解途径在两个恒化器中占主导地位：通过Stickland反应在恒化器I中偶联降解氨基酸，通过氨基酸降解菌和氢营养产甲烷菌在恒化器2中的互养协会解偶联降解氨基酸。
Two mesophilic anaerobic chemostats, one without added Ni2+ and Co2+ (chemostat 1) and the other with added Ni2+ and Co2+ (chemostat 2), were supplied with synthetic wastewater containing bovine serum albumin (BSA) as the sole carbon and energy source in order to study the capacity of protein degradation, microbial community structure and the effects of the addition of trace metals. Volatile fatty acids and ammonia were the main products of chemostat 1, while methane, CO2 and ammonia were the main products of chemostat 2, and critical dilution rates of 0.15 d(-1) and 0.08 d(-1) were obtained, respectively. Fluorescence in situ hybridization (FISH) with archaeal and bacterial domain-specific probes showed that archaeal cells were very limited in chemostat I while large populations of several types of archaeal cells were present in chemostat 2. Phylogenetic analyses based on 16S rRNA gene clonal sequences, DGGE, and quantitative real-time polymerase chain reaction (PCR) showed that, within the domain Archaea, methanogens affiliated with the genera Methanosaeta and Methanoculleus were predominant in chemostat 2. Within the domain Bacteria, rRNA genes obtained from chemostat I were affiliated with the three phyla; Firmicutes (43%), Bacteroidetes (50%) and Proteobacteria (7%). A total of 56% of rRNA genes obtained from chemostat 2 was affiliated with the three phyla, Firmicutes (32%), Bacteroidetes (11%) and Proteobacteria (13%) while 44% of rRNA genes remained unclassified. Phylogenetically distinct clones were obtained in these two chemostats, suggesting that different protein degradation pathways were dominant in the two chemostats: coupled degradation of amino acids via the Stickland reaction in chemostat I and uncoupled degradation of amino acids via syntrophic association of amino acid degraders and hydrogenotrophic methanogens in chemostat 2.