Proximate Composition of Banana and Pineapple Wine Fermented by Meyerozyma guilliermondii and Pichia guilliermondii

Wine is an alcoholic beverage produced from juices of a variety of fruits by the fermentative action of microorganisms. There is a quest for alternative sources of must for wine fermentation, however, the proximate composition should be known to ascertain how nutritious it is. The study was thus aimed at determining the proximate composition of the wines fermented by Meyerozyma guilliermondii and Pichia guilliermondii. Two isolates identified as Meyerozyma guilliermondii strain 1621 and Pichia guilliermondii strain PAX-PAT 18S were used for the fermentation of the substrates obtained from a mixture of pineapple and banana pulp. The fermentation process was for 28 days, followed by a series of racking, clarification, and aging process which was for 2 months. The fermentation process comprised two setups: one was fermented by Meyerozyma guilliermondii strain 1621 and the other by Pichia guilliermondii strain PAX-PAT 18S. The process was monitored and the proximate analysis of the wines was ascertained. The wine produced by Meyerozyma guilliermondii strain 1621 had a moisture content of 82.56 %, ash content of 1.41 %, fat content of 0.08 %, protein content of 1.43%, and carbohydrate content of 9.77%. The wine produced by Pichia guilliermondii strain PAX-PAT 18S had a moisture content of 79.51%, ash content of 1.19%, fat content of 0.15%, protein content of 0.49%, and carbohydrate content of 10.49%. Although this study is not exhaustive, it shows that wines with good nutritional composition can be successfully produced using Meyerozyma guilliermondii strain 1621 and Pichia guilliermondii strain PAX-PAT 18S.

Isolation, taxonomic identification and investigation of the biotechnological potential of wild-type Meyerozyma guilliermondii associated with amazonian termites able to ferment D-xylose / Isolamento, identificação taxonômica e investigação do potencial biotecnológico de linhagem selvagem de Meyerozyma guilliermondii fermentadora de d-xilose associada a cupins da Amazônia

A wild-type yeast that could ferment D-xylose was isolated from the abdominal content of Nasutitermes sp. collected in the Central Amazon rainforest using sugarcane bagasse hemicellulosic hydrolyzate (SBHH) as selective medium. The yeast was identified as Meyerozyma guilliermondii. Its ability to ferment D-xylose was assessed using liquid medium containing Durham tubes. A fermentometer assay showed a low ethanol yield using D-xylose as the carbon source. Cell viability after heat shock and ethanol shock was 39.8% and 56.0%, respectively. Cultivation in SBHH (pH = 5.0) showed its capability to perform saccharification of this substrate, increasing total reducing sugar concentration to 42.6%. The log phase was observed between 36 and 108 hours of cultivation with a highest specific growth rate (µMAX) of 0.10 h-1. After 120 hours, 79.5% of total reducing sugar was consumed giving a biomass yield of 0.52 g/g. The final pH of SBHH (7.6) showed that M. guilliermondii was able to neutralize the acids of this substrate. These results agree with some predictions in the early eighties, which stated that investigations about microbial content of termite guts would provide new tools for bioconversion of lignocellulosic biomass to fuels and other added-value chemicals. This work is the first report for this species associated with termites in the Amazonian habitat.

Uma levedura selvagem fermentadora de D-xilose foi isolada do conteúdo abdominal de Nasutitermes sp., coletado na Amazônia Central usando Hidrolisado Hemicelulósico de Bagaço de Cana-de-açúcar (HHCA) como meio seletivo. A levedura foi identificada como Meyerozyma guilliermondii. Sua capacidade de fermentar D-xilose foi avaliada usando meio líquido contendo tubos de Durham. O isolado demonstrou moderada tolerância ao calor e ao etanol, com viabilidade celular de 39,8% e 56,0%, respectivamente, após submetida a estes fatores limitantes. O ensaio em fermentômetro demonstrou baixo rendimento de etanol usando D-xilose como fonte de carbono. O cultivo em HHCA (pH = 5,0) demonstrou sua capacidade de executar sacarificação e neutralização deste substrato, com aumento da concentração de açúcar redutor total em 42,6% e elevação do pH para 7,6. A fase log foi observada entre 36 e 108 horas de cultivo, com máxima taxa de crescimento específico (µMAX) de 0,10 h-1. Depois de 120 horas, 79,5% do açúcar redutor total foi consumido, com rendimento de biomassa de 0,52 g/g. Estes resultados endossam as predições de alguns autores, os quais propuseram, no início dos anos 80, que a investigação da microbiota intestinal de cupins proveria novas ferramentas para utilização de biomassa lignocelulósica e seus derivados. Este trabalho é o primeiro a reportar a ocorrência de Meyerozyma guilliermondii associada a cupins da Amazônia Central.