Wang Boying, Rutherfurd-Markwick Kay, Naren Naran, Zhang Xue-Xian, Mutukumira Anthony N
School of Food and Advanced Technology, Massey University, Auckland 0745, New Zealand.
School of Health Sciences, College of Health, Massey University, Auckland 0745, New Zealand.
Foods. 2023 Jun 8;12(12):2314. doi: 10.3390/foods12122314.
Kombucha is a popular sparkling sugared tea, fermented by a symbiotic culture of acetic acid bacteria (AAB) and yeast. The demand for kombucha continues to increase worldwide, mainly due to its perceived health benefits and appealing sensory properties. This study isolated and characterised the dominant AAB and yeast from a starter culture and kombucha broth after 0, 1, 3, 5, 7, 9, 11, and 14 days of fermentation at ambient temperature (22 °C). Yeast and AAB were isolated from the Kombucha samples using glucose yeast extract mannitol ethanol acetic acid (GYMEA) and yeast extract glucose chloramphenicol (YGC) media, respectively. The phenotypic and taxonomic identification of AAB and yeast were determined by morphological and biochemical characterisation, followed by a sequence analysis of the ribosomal RNA gene (16S rRNA for AAB and ITS for yeast). The changes in the microbial composition were associated with variations in the physico-chemical characteristics of kombucha tea, such as pH, titratable acidity, and total soluble solids (TSS). During fermentation, the acidity increased and the TSS decreased. The yield, moisture content, and water activity of the cellulosic pellicles which had developed at the end of fermentation were attributed to the presence of AAB. The dominant AAB species in the cellulosic pellicles and kombucha broth were identified as The yeast isolates belonged to and .
康普茶是一种广受欢迎的带气泡的甜茶，由醋酸菌（AAB）和酵母的共生培养物发酵而成。全球对康普茶的需求持续增长，主要是因为其被认为有益健康且具有吸引人的感官特性。本研究从室温（22°C）下发酵0、1、3、5、7、9、11和14天后的起始培养物和康普茶汤中分离并鉴定了优势醋酸菌和酵母。分别使用葡萄糖酵母提取物甘露醇乙醇乙酸（GYMEA）培养基和酵母提取物葡萄糖氯霉素（YGC）培养基从康普茶样品中分离酵母和醋酸菌。通过形态学和生化特征鉴定醋酸菌和酵母的表型和分类学，随后对核糖体RNA基因进行序列分析（醋酸菌为16S rRNA，酵母为ITS）。微生物组成的变化与康普茶的理化特性变化相关，如pH值、可滴定酸度和总可溶性固形物（TSS）。在发酵过程中，酸度增加而TSS降低。发酵结束时形成的纤维素菌膜的产量、水分含量和水分活度归因于醋酸菌的存在。纤维素菌膜和康普茶汤中的优势醋酸菌物种被鉴定为 酵母分离株属于 和 。
