一株酸鱼联合乳杆菌H2的分离鉴定及代谢特性研究

Isolation and Identification of a Ligilactobacillus Acidipiscis Strain H2 and Its Metabolic Characteristics

产乳酸菌在白酒酿造中具有调节发酵过程、改善口感、抑制有害微生物生长和促进酒质稳定性等重要功能,对于白酒的质量和口感的形成具有重要的影响。为了获得窖泥中新的产乳酸菌,本文以浓香型窖泥为供试样品分离纯化产乳酸菌株,并进行分类学鉴定及代谢特性研究。结果表明,从窖泥中筛选获得6株产乳酸菌,分别为海氏芽孢杆菌(Bacillus haynesii H1)、联合乳酸杆菌(Ligilactobacillus acidipiscis H2)、发酵互营球菌(Novisyntrophococcus fermenticellae H3)、产孢梭菌(Clostridium sporogenes H4、H5)和氨戊酸厌氧菌(Anaerocolumna aminovalerica H6)。其中H2具有更优的代谢产酸性能。该菌的最适碳源为葡萄糖和果糖,主要产物为乳酸,属于同型乳酸发酵细菌。H2菌株在葡萄糖浓度为10 g/L和初始p H 7.5、接种量为10%、培养温度为37℃时发酵7天的乳酸产量为10.98 g/L。该菌最适的p H范围是5.5~7.5,在p H4.5以下活性显著降低,具有与己酸菌共培养提高窖泥质量和调控窖泥群落的潜力。

Lactic acid bacteria(LAB)play an important role in regulating the fermentation process,improving the taste,inhibiting the growth of harmful microorganisms and promoting the stability of liquor quality in Baijiu brewing.Consequently,they have a significant impact impact on the overall quality and taste of Baijiu.In this study,we employed the strong-flavor pit mud as experimental sample for isolating and purifying valuable probiotic LAB.Subsequently,we conducted taxonomic identification and metabolic characteristics analyses.The results showed that 6 LAB strains were isolated from pit mud,namely Bacillus haynesii H1,Ligilactobacillus acidipiscis H2,Novisyntrophococcus fermenticellae H3,Clostridium sporogenes H4,H5 and Anaerocolumna aminovalerica H6,respectively.Among these strains,H2 exhibited superior performance in metabolic acid production compared to other strains.The bacteria demonstrated optimal utilization of glucose and fructose as carbon sources,resulting in lactic acid as the primary product.It can be categorized as a homolactic fermentation bacteria.Notably,strain H2 yielded a lactic acid production of 10.98 g/L after 7-day fermentation period at a glucose concentration of 10 g/L,an initial pH 7.5,an inoculation amount of 10%,and a culture temperature of 37℃.The strain exhibited an optimum pH range of 5.5~7.5,with activity significantly declining below pH4.5.Strain H2 exhibits potential for co-culturing with caproic acid bacteria to improve the quality of pit mud and regulate the pit mud community.