Dynamics of Functional Genes and Bacterial Community during Bioremediation of Diesel-Contaminated Soil Amended with Compost

Abstract

Makgeolli is a traditional rice wine favored by the general public in Korea. This study investigated the fermentation and sensory characteristics of using wild yeast strains for brewing makgeolli. A non-Saccharomyces cerevisiae strain was isolated from nuruk and termed Y197-13. It showed 98% similarity to Pichia anomala and had an optimal growth temperature of 25 o C. Makgeolli was manufactured using koji, jinju nuruk, and improved nuruk as fermentation agents. Y197-13 makgeolli brewed with koji had alcohol and solids contents of 11.1% and 13.9%, respectively. Sweet sensory characteristics were attributed to residual sugars in makgeolli with 6% alcohol. The makgeolli had a fresh sour taste and carbonated taste. Volatile component analysis showed the isoamyl alcohol, phenylethyl alcohol, isoamyl acetate, and fatty acid, including ethyl oleate and ethyl linoleate, relative peak area was higher in Y197-13 makgeolli than in makgeolli with Saccharomyces cerevisiae. These results suggest the wild yeast, Y197-13, as a candidate for brewing makgeolli.

Microbiological Characteristics of Wild Yeast Strain Pichia anomala Y197-13 for Brewing Makgeolli

“…The 18S rRNA gene sequence analysis indicated the strain Y197-13 (GenBank: JX566694, 1 ctgcngaagg nncatnatag tattctattg ccagcgctta attgcgcggc gataaacctt 61 acacacattg tctagttttt ttgaactttg ctttgggtgc atcagcctag ctgcgtgccc 121 aaaggtctaa acacattttt ttaatgttaa aacctttaac caatagtcat gaaaattttt 181 aacaaaaatt aaaatcttca aaactttcaa caacggatct cttggttctc gcaacgatga 241 agaacgcagc gaaatgcgat acgtattgtg aattgcagat tttcgtgaat catcgaatct 301 ttgaacgcac attgcaccct ctggtattcc agagggtatg cctgtttgag cgtcatttct 361 ctctcaaacc ttcgggtttg gtattgagtg atactctgtc aagggttaac ttgaaatatt 421 gacttagcaa gagtgtacta ataagcagtc tttctgaaat aatgtattag gttcttccaa 481 ctcgttatat cagctaggca ggtttagaag tattttaggc tcggcttaac aacaataaac 541 taaaagtttg acctcaaatc aggtaggact acccnntgnn cttaagca) is most closely related to the Wickerhamomyces anomalus with similarity levels of 98% (match 522 bp/total 530 bp) [4]; Wickerhamomyces anomalus , with the synonym Pichia anomala . Based on the phylogenetic tree, these reference strains include P. anomala CBS 5759 T and W. sydowiorum CBS 5995 T , were the phylogenetically closest taxa (Fig.…”

“…The 18S rRNA gene sequence of strain Y197-13 was amplified from genomic DNA using the universal primers ITS1 and ITS4 [10] and the purified PCR products were sequenced by Macrogen (Seoul, Korea) according to the previous study [4]. The sequences (ITS1, 1,258 bp; ITS4, 1,401 bp) of the 18S rRNA genes were assembled using SeqManII software version 5.0 (DNAStar, Inc., Madison, WI, USA).…”

“…Therefore, in order to improve the quality of traditional Korean alcoholic beverages, study of the microorganisms present in Nuruk is needed. Accordingly, the previous study [4] was conducted in order to identify novel yeasts that can be used in brewing Makgeolli . Unlike previous studies that identified yeasts that yield a high alcohol content [5], we isolated the wild yeast strain, Pichia anomala Y197-13, from Nuruk , which has characteristics similar to those of Makgeolli brewed with S. cerevisiae Y98-5, despite their low alcohol production.…”

“…Of particular interest, strain Y197-13 did not form a biofilm in Koji extract medium and brewed Makgeolli was expected to have an appropriate flavor in contrast to the plain flavor of conventional Makgeolli [4]. In this study, the morphological characteristics, including flocculation, carbon source assimilation, cellular fatty acid composition, alcohol resistance, and glucose tolerance characteristics of strain Y197-13 that could potentially be used in brewing of Makgeolli were investigated.…”

Diversity, Saccharification Capacity, and Toxigenicity Analyses of Fungal Isolates in Nuruk

“…곰팡이의 전 분당화능에 의해 만들어진 당류는 효모에 의한 알코올 생 산에 사용된다. 주로 누룩에 생육하는 효모로는 Saccharomyces cerevisiae를 비롯하여 Pichia jadinii [1], P. anomala [3,4] 등이 분리된 바 있으며, 막걸리의 PCR-DGGE 분석 을 통하여 P. kudriavzevii가 발효초기의 우점균임이 밝혀진 바 있다 [5]. Saccharomycopsis fibuligera도 다수의 누룩에서 발견되었는데, 특이하게도 알코올발효능 대신 높은 당화 능을 가지고 있는 것으로 보고되었다 [6].…”