Microbial Community Dynamics During the Non-filamentous Fungi Growth-Based Fermentation Process of Miang, a Traditional Fermented Tea of North Thailand and Their Product Characterizations

Abstract

Miang , a traditional fermented tea leaf ( Camellia sinensis var. assamica ) consumed in northern Thailand, was simulated in laboratory conditions using non-filamentous fungi process (NFP) and microbial community was periodically investigated for over 6 months of fermentation by both culture-dependent and -independent techniques. The viable cell numbers of lactic acid bacteria (LAB), yeast, and Bacillus enumerated by the culture-dependent technique markedly surged over 3 days of initial fermentation and then smoothly declined by the end of fermentation. LAB were found as the main microbial population throughout the fermentation period followed by yeast and Bacillus . High-throughput sequencing of microbial community during fermentation revealed that Firmicutes (86.9–96.0%) and Proteobacteria (4.0–12.4%) were the dominant bacterial phyla, whereas Ascomycota was found to be the main fungal phylum with an abundance of over 99% in the fungal community. The dominant bacterial family was Lactobacillaceae (39.7–79.5%) followed by Acetobacteraceae , Enterobacteriaceae , Bacillaceae , Aeromonadaceae , Staphylococcaceae , Moraxellaceae , Clostridiaceae , Exiguobacteraceae , Streptococcaceae , and Halomonadaceae . Meanwhile, the main fungal family was incertae sedis Saccharomycetales (75.6–90.5%) followed by Pichiaceae , Pleosporaceae , Botryosphaeriaceae , Davidiellaceae , Mycosphaerellaceae , and Saccharomycodaceae . In addition, Lactobacillus (29.2–77.2%) and Acetobacter (3.8–22.8%), and the unicellular fungi, Candida (72.5–89.0%) and Pichia (8.1–14.9%), were the predominant genera during the fermentation process. The profiles of physical and chemical properties such as Miang texture, pH, organic acids, polysaccharide-degrading enzyme activities, and bioactive compounds have rationally indicated the microbial fermentation involvement. β-Mannanase and pectinase were assumed to be the key microbial enzymes involved in the Miang fermentation process. Total tannin and total polyphenol contents were relatively proportional to the antioxidant activity. Lactic acid and butyric acid reached maximum of 50.9 and 48.9 mg/g dry weight (dw) at 9 and 63 days of fermentation, respectively. This study provided essential information for deeper understanding of the Miang fermentation process based ...

Microbial Composition of SCOBY Starter Cultures Used by Commercial Kombucha Brewers in North America

“…Bacterial qPCR was performed using 926f (5′-AAACTCAAKGAATTGACGG-3′) and 1062r (5′-CTCACRRCACGAGCTGAC-3′) primers [ 29 ], with amplification conditions as follows: 5 min @ 95 °C, then 40 cycles (15 s at 95 °C, 15 s at 61.5 °C, 20 s at 72 °C) and a final extension for 5 min at 72 °C.…”

Acid Stable Yeast Cell-Associated Tannase with High Capability in Gallated Catechin Biotransformation

“…The profile of Miang catechins has been described in a previous study. There were dynamic changes in Miang catechin, especially the biotransformation of EGCG to EGC and ECG to EC during the production process [ 16 ]. With regard to the substrate specificity results, all CATs could be used for biotransformation [ 31 ], antioxidant activity enhancement, and extraction of tea catechins [ 32 ], as well as the improvement of the sweet aftertaste of tea products [ 4 ].…”

“…Unlike other types of tea, Miang is a unique product that is known as chewing tea or eating tea, but it has become less popular among younger generations [ 14 ]. The ethnic roots of the Miang production process in northern Thailand is a potential source of a number of health-related bioactive compounds [ 15 , 16 , 17 ], specifically tea catechins which continue to attract research interest. However, the Miang production process must be conserved and/or develop to produce a more acceptable product for younger generations.…”

Comparison of Phenolic Contents and Scavenging Activities of Miang Extracts Derived from Filamentous and Non-Filamentous Fungi-Based Fermentation Processes

“…filamentous fungi growth-based process (FFP) and the non-filamentous fungi growth-based process (NFP), have found their niches in the eastern (including Chiang Rai, Phayao, Lampang, Phrae, and Nan provinces) and western (Chiang Mai, Lumphun, and Mae Hong Son provinces) regions of northern Thailand (ancient eastern and western Lanna Kingdom) [6]. Kodchasee et al [7] and Unban et al [8] have extensively investigated and simulated FFP and NFP fermentation over an extended period using fresh tea leaves sourced from Mae-lua village, Phrae Province, and Papae district, Chiang Mai Province, Thailand respectively. These sampling areas have been established to produce significant concentrations of bioactive compounds in Miang [9] as well as possess well acceptable product quality compared to Miang from other plantation areas (unpublished data).…”