Yeasts from Canastra cheese production process: Isolation and evaluation of their potential for cheese whey fermentation

Canastra cheese is a cheese with geographical indication recognized by the Brazilian National Institute of Industrial Protection under number IG201002. It is produced in seven municipalities in the state of Minas Gerais in a region called Serra da Canastra. In thiswork, samples of milk, “pingo” (natural starter),whey and Canastra cheese were collected on a farm inMedeiros-MG/Brazil to evaluate the yeast microbiota and select yeasts for whey fermentation to produce ethanol and volatile aromatic compounds of relevance in the production of cheese. Thirtynine isolates capable of fermenting lactose in a synthetic medium were identified by MALDI-TOF as Kluyveromyces lactis (29), Torulaspora delbrueckii (7) and Candida intermedia (3). Eleven isolates of K. lactis and three of T. delbrueckii efficiently fermented lactose until 4th day, and due to this reason were selected for cheese whey fermentation with Brix 12, 14 and 18. Generally, the isolates T. delbrueckii B14, B35, and B20 and K. lactis B10 were the most effective regardless of the initial Brix value. The identification of these four isolates by MALDI TOF was confirmed by sequencing of the ITS region. In the fermentation of cheese whey 14 Brix, T. delbrueckii B14 and B35, respectively yielded 24.06 g/L and 16.45 g/L of ethanol, while K. lactis B10 was more efficient in the consumption of lactose. In sequential culture with K. lactis B10 inoculated 48 h after T. delbrueckii B14, 97.82% of the total sugars were consumed resulting in the production of 19.81 g/L ethanol and 39 aromatic volatile compounds. The most abundant compounds were 3-methyl-1-butanol, octanoic acid and ethyl decanoate, which are reported as important for the aroma and flavor of cheeses. Based in our results, B10 isolate inoculated 48 h after B14 isolate is a promising yeast inoculum to be used for fermentation of dairy substrates.The authors thank CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico do Brasil), CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) and FAPEMIG (Fundação de Amparo à Pesquisa do Estado de Minas Gerais) for financial support. The authors also thank J.C Amorim for her help in MALDI TOF analysis and Dr. P.S Geraldino for her help in sequences analysis

Physico-chemical and microbiological characterization of corn and rice ‘calugi’ produced by Brazilian Amerindian people

Abstract‘Calugi’ is a fermented porridge that is produced from corn and rice by Javaé Amerindians. Samples of this porridge were chemically and microbiologically characterized. The microbial population was composed of yeasts, aerobic mesophilic bacteria (AMB), lactic acid bacteria (LAB), acetic acid bacteria (AAB) and some enterobacteria. The population of lactic acid bacteria (LAB), acetic acid bacteria (AAB) and yeasts increased slightly during ‘calugi’ fermentation. During the initial fermentation period (12 and 24h), counts of the bacterial population (LAB, AMB and enterobacteria) and yeast increased. After 48h of fermentation, the population of mesophilic bacteria was 5.06logCFU/mL; lactic acid bacteria (LAB), 4.69logCFU/mL; yeast, 4.37logCFU/mL; enterobacteria, 3.29logCFU/mL and acid acetic bacteria (AAB), 3.14logCFU/mL. During the fermentation process, Lactobacillus plantarum, Streptococcus salivarius, Streptococcus parasanguis, Weissella confusa, Enterobacter cloacae, Bacillus cereus and Bacillus sp. and the yeasts Saccharomyces cerevisiae, Pichia fermentans and Candida sp. were detected by PCR-DGGE. The LAB were dominant during the process and were likely most responsible for the reduction in pH value, which permitted yeast growth. Carbohydrates (70.48g/L — maltose), alcohols (1.70g/L — glycerol) and acids (4.56g/L — acid lactic) were identified by HPLC. Fifteen volatile compounds were identified and quantified by GC-FID. From the fermentation, acetaldehyde, 1-1-diethoxyethane, isobutyl acetate, ethyl acetate, furfuryl alcohol and nonanoic acid were identified, with maximum concentrations of 457.02μg/L, 73.96μg/L, 54.03μg/L, 24.82μg/L, 755.82μg/L, 61.85μg/L, respectively

Production and characterization of a new sweet Sorghum distilled beverage

Sweet sorghum is a culture that has received increasing attention in the last years. In many countries, genetic breeding programs have been developed seeking increases in the production of juice and sugars for alcoholic fermentation. In our study, S. cerevisiae and M. caribbica were evaluated to produce a distilled beverage from sweet sorghum, which was chemically and sensorially characterized. Both inocula and genotype BRS 506 were selected to produce the sweet sorghum spirit due to their high sugar conversion, ethanol yield, efficiency and productivity. The produced novel sorghum spirit was chemically and sensorially characterized. Fifty-five volatile compounds were identified by GCMS, most of them belonging to the groups of esters and higher alcohols, which are desirable due to their fruity aromatic descriptors in distilled beverages. The sweet sorghum spirit produced with S. cerevisiae presented more volatile acids (9431.86 µg/L), aldehydes (331.93 µg/L) and terpenes (4881 µg/L). In contrast, the spirit produced with mixed inoculum showed 58,021.27 µg/L of esters and 9717.07 µg/L of higher alcohols. The mixed inoculum improved the production of desirable volatile compounds, resulting in slightly greater acceptance in the sensorial analysis with a higher index of purchase intention. Based on our results, the sweet sorghum proved to be a good substrate for alcoholic fermentation to produce a spirit, which may represent an interesting alternative in the market of distilled beverages.This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001. The authors also would like to thank Conselho Nacional de Desenvolvimento Científico e Tecnolo ´gico do Brasil (CNPq) and Fundação de Amparo à Pesquisa de MG (FAPEMIG) for financial support.info:eu-repo/semantics/publishedVersio

Interaction of Saccharomyces cerevisiae and Lactococcus lactis in the fermentation and quality of artisanal cachaça

Lactococcus lactis and Saccharomyces cerevisiae in co-culture were evaluated during sugar cane fermentantion for cachaça production. The inocula containing L. lactis UFLA CA 312 and S. cerevisiae UFLA CA 11 were used in the population of approximately 105 CFU mL-1 and 108 CFU mL-1,  respectively. The sugar cane medium plus 1% of yeast extract (SCM) was efficient for growth of L. lactis UFLA CA 312 and S. cerevisiae UFLA CA 11 (letter b -Tukey test). In flasks and vats fermentation the growth of UFLA CA 11 was not negatively influenced by L. lactis UFLA CA 312. However, after 19 h of fermentation, bacterial population showed a slight decrease. Considering parameters higher alcohols and aldehydes, cachaça produced by pure culture of S. cerevisiae was similar to cachaça produced by mixed culture. Cachaça produced by mixed culture showed high values of volatile acidity (letter b -Scott-Knott test) being characterized by this parameters in the principal component analysis. High percentage of acceptance (81.10%) for the attribute aroma was observed in samples from cachaça produced by mixed culture

Adubação verde no controle de plantas invasoras nas culturas de alface-americana e de repolho

Objetivou-se com este trabalho verificar os possíveis efeitos físicos e/ou alelopáticos da adubação verde no manejo de plantas invasoras nas culturas posteriores de alface-americana e de repolho, visando à conversão para o sistema orgânico de cultivo. O experimento foi instalado no Setor de Olericultura da Universidade Federal de Lavras (UFLA), em Lavras MG, no período de dezembro de 2001 a agosto de 2002. O delineamento experimental adotado foi o de blocos casualizados em esquema fatorial 4x2, com 3 repetições. O primeiro fator foi constituído pelas leguminosas mucuna-preta (Stizolobium aterrimum, Piper e Tracy), feijão-de-porco (Canavalia ensiformes DC), crotalária juncea (Crotalaria juncea L.)e pela testemunha (vegetação espontânea) e o segundo fator, pelas culturas de alface-americana Raider e repolho Kenzan . A parcela experimental teve a dimensão de 4 x 3 m. Pelos resultados obtidos, nas condições em que foi desenvolvido o trabalho, pode-se concluir que as espécies utilizadas mostraram-se eficientes no controle de tiririca (Cyperus rotundus L.), especialmente a mucuna-preta e o feijão-de-porco, possivelmente por efeito alelopático, e o cultivo de repolho proporcionou maior redução da infestação de tiririca do que o de alface-americana.The objective of this work was to verify allelopathical and physical effects of black velvet bean (Stizolobium aterrimum Piper e Tracy), jack bean (Canavalia ensiformes DC) and sunnhep (Crotalaria juncea L.) on the development of the weeds in American Lettuce and Cabbage crops. The experiment was performed at the Vegetables Sector of Universidade Federal de Lavras, in Lavras MG, from December 2001 to August 2002. The experimental design used was random blocks in the 4 x 2 factorial scheme with 3 repetitions. One factor consisted of the three leguminous, black velvet bean, jack bean and sunnhep, and the control (spontaneous vegetation); the other factor consisted of the cultures of Lettuce ( Raider cultivar) and Cabbage ( Kenzan cultivar). The results showed that the black velvet bean and jack bean controlled the sedge and the cabbage cultivation reduced the sedge infestation

Evaluation of stress tolerance and fermentative behavior of indigenous Saccharomyces cerevisiae

Sixty six indigenous Saccharomyces cerevisiae strains were evaluated in stressful conditions (temperature, osmolarity, sulphite and ethanol tolerance) and also ability to flocculate. Eighteen strains showed tolerant characteristics to these stressful conditions, growing at 42 ºC, in 0.04% sulphite, 1 mol L-1 NaCl and 12% ethanol. No flocculent characteristics were observed. These strains were evaluated according to their fermentative performance in sugar cane juice. The conversion factors of substrates into ethanol (Yp/s), glycerol (Yg/s) and acetic acid (Yac/s), were calculated. The highest values of Yp/s in sugar cane juice fermentation were obtained by four strains, one isolated from fruit (0.46) and the others from sugar cane (0.45, 0.44 and 0.43). These values were higher than the value obtained using traditional yeast (0.38) currently employed in the Brazilian bioethanol industry. The parameters Yg/s and Yac/s were low for all strains. The UFLA FW221 presented the higher values for parameter related to bioethanol production. Thus, it was tested in co-culture with Lactobacillus fermentum. Besides this, a 20-L vessel for five consecutive batches of fermentation was performed. This strain was genetically stable and remained viable during all batches, producing high amounts of ethanol. The UFLA FW221 isolated from fruit was suitable to produce bioethanol in sugar cane juice. Therefore, the study of the biodiversity of yeasts from different environmental can reveal strains with desired characteristics to industrial applications

Endophytic fungi from Brachiaria grasses in Brazil and preliminary screening of Sclerotinia sclerotiorum antagonists

Fungal endophytes of Brachiaria, a nonhost of Sclerotinia sclerotiorum, may harbor species with antagonistic effects against this plant pathogen. The objective of this work was to investigate the diversity of endophytic fungi associated with different Brachiaria species and hybrids and evaluate their potential to inhibit the plant pathogen S. sclerotiorum. Stem samples from 39 Brachiaria spp. plants were collected in pasture fields and experimental areas of three states of Brazil resulting in 74 endophytes isolated. Twenty-eight species were identified by sequences of the Internal Transcribed Spacer (ITS) and 18S rDNA regions. Paraconiothyrium sp. was the most abundant endophyte, accounting for 24 % (14 isolates) of total, and it was isolated from B. ruziziensis, B. decumbens, B. humidicola, and B. brizantha. Phoma sorghina was the second most abundant taxon, followed by Sarocladium strictum, and Plenodomus sp. In vitro analyses showed that Paraconiothyrium sp., Sarocladium kiliense, Acremonium curvulum, Setophoma terrestris, Dissoconium sp., and Cladosporium flabelliforme exhibited antagonistic activity against S. sclerotiorum, with percentages of growth inhibition ranging from 25 to 60 (p < 0.05). Paraconiothyrium sp. BBXE1 (60 %), BBPB4.1 (60 %), BCMT4.1 (54 %), and S. kiliense (54 %) showed the highest values of Antagonism Percentages (AP). Therefore, fungi with inhibitory activity against S. sclerotiorum such as Paraconiothyrium sp. are naturally endophytic in Brachiaria grasses