酱香型白酒发酵中两株主要乳酸菌对酿造微生物群体的影响

Impacts of two main lactic acid bacteria on microbial communities during Chinese Maotai-flavor liquor fermentation

【目的】研究从酱香型白酒发酵酒醅中分离得到的2株主要乳酸菌Lactobacillus homohiochii XJ-L1和Lactobacillus buchneri XJ-L2对酱香型白酒发酵中酿造微生物群体的作用,并探索该种相互作用对酱香型白酒品质的影响。【方法】结合抑菌实验和组合发酵实验研究L.homohiochii XJ-L1和L.buchneri XJ-L2对酿造微生物群体生长的影响,通过对纯培养和共培养体系中代谢物的比较,研究2株优势乳酸菌对主要酿造酵母风味相关代谢产物的影响。【结果】L.buchneri XJ-L2能够抑制3株芽孢杆菌(Bacillus amyloliquefaciens XJ-B1,Bacillus subtilis XJ-B2,Bacillus licheniformis XJ-B3)、5株霉菌(Aspergillus oryzae XJ-M1,Aspergillus niger XJ-M2,Aspergillus flavus XJ-M3,Aspergillus albicans XJ-M4,Rhizopus oryzae XJ-M5)、2株酵母(Schizosaccharomyces pombe XJ-Y4,Geotrichum candidum XJ-Y5)的生长;L.homohiochii XJ-L1和L.buchneri XJ-L2能够促进3株主要酵母(Saccharomyces cerevisiae XJ-Y1,Zygosaccharomyces bailii XJ-Y2,Pichia galeiformis XJ-Y3)的生长,同时促进其酸类、醇类、酯类等风味物质的代谢。【结论】L.homohiochii XJ-L1和L.buchneri XJ-L2可促进3株主要酵母的生长代谢,同时L.buchneri XJ-L2明显抑制细菌、霉菌和少数酵母的生长,以此促进和维持主要酵母在酱香型白酒发酵过程中的生态地位,从而影响酒中酸类、醇类、酯类等风味物质的形成,保证酱香型白酒的品质。因此,适当比例的乳酸菌对维持酿造微生物区系平衡,生产典型酱香品质白酒具有重要意义。

[Objective] Objectives of this study were to investigate the impacts of two major lactic acid bacteria（L. homohiochii XJ-L1 and L. buchneri XJ-L2） on the microbial communities and flavor quality of Chinese Maotai-flavor liquor. [Methods] Bacteriostatic tests in vitro and mixed culture fermentation were carried out to investigate the interactions between main lactic acid bacteria and the other major microorganisms during fermentation. [Results] L. buchneri XJ-L2 could inhibit the growth of three Bacillus strains（B. amyloliquefaciens XJ-B1, B. subtilis XJ-B2, B. licheniformis XJ-B3）, five mold strains（A. oryzae XJ-M1, A. niger XJ-M2, A. flavus XJ-M3, A. albicans XJ-M4, R. oryzae XJ-M5） and two yeasts（Sc. pombe XJ-Y4, G. candidum XJ-Y5）. L. homohiochii XJ-L1 and L. buchneri XJ-L2 could promote the growth of three main yeasts（S. cerevisiae XJ-Y1, Z. bailii XJ-Y2, P. galeiformis XJ-Y3）, and benefited for the production of acids, alcohols, esters etc. [Conclusion] The two main lactic acid bacteria, L. homohiochii XJ-L1 and L. buchneri XJ-L2, could maintain the ecological status of the main yeasts in the fermentation process through promoting the growth of three main yeasts and inhibiting bacillus, mold and few yeasts（L. buchneri XJ-L2 was more obvious）. In addition, lactic acid bacteria affected the formation of acids, alcohols, esters and other flavor compounds and benefited for Maotai-flavor liquor fermentation. The appropriate proportion of lactic acid bacteria could enhance the balance of fermentation microflora. It is significant for the aroma production of Chinese Maotai-flavor liquor.