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Health-conscious consumers are looking for functional foods to improve their body's well-being. Kefir-based foods provide improvements in quality of life. Kefir has a nutritional and probiotic function. This study aimed to elaborate on kefir-based Petit Suisse flavored with nibs and cocoa honey, as well as to evaluate the physicochemical and microbiological parameters and sensorial acceptance. The kefir-based Petit Suisse developed in this study proved to be a viable proposition as a food source. All items listed in the sensory analysis received positive ratings by the majority of the evaluating public, which made the product exceed the value established as a criterion for acceptance. Kefir-based Petit Suisse flavored with nibs and cocoa honey can be considered a promising product for the market with nutritional values and probiotic potential.

Psychobiotics are probiotic microorganisms that beneficially affect the central nervous system functions mediated by the gut-brain axis, improving the host's immune system. Psychobiotic microorganisms can regulate brain pathways and serotonin production (mood controller). The main microbial genera with psychobiotic characteristics are

The use of non-dairy matrices for probiotic delivery can be beneficial for vegetarian, vegan and lactose intolerant consumers. Stevia rebaudiana extract can be used as sweetener to replace sucrose for glucose intolerants. This research evaluated the use of kefir grains to prepare a low-calorie, fruit-based kefir beverage. Fermentation was carried out by inoculating kefir grains into a mixture of mango and umbu pulps. Two beverages, one containing sucrose, and the other, stevia, were characterized according to their proximate composition and submitted to a 30-day shelf-life period at 5°C, evaluating lactic acid bacteria, yeasts, pH, acidity, color parameters, soluble solids, ascorbic acid, sensory acceptance, and purchase intention every 10 days. Lactic and acetic acids were analyzed at the beginning and end of the shelf-life. Both beverages showed probiotic potential. The stevia-sweetened beverage had lower calorie content and good sensory acceptance. These results support the possibility to develop low-calorie, fruit-based kefir beverages.

Introduction: Communication between intestine-brain axis is complex and uses different pathways. This communication forms a bidirectional axis whose equilibrium depends on the composition of the microbial community that inhabits the intestines. This ecosystem has a modulator role on the intestine-brain axis. Because of this, intestine-brain axis becomes a fascinating growing study area. The intestinal dysbiosis hurts the host's health and can lead to several psychiatric diseases. Aim: The present opinion described highlight an emerging theme in medicine, the interesting communication that is established between the intestine-brain axis. The function that intestinal probiotic microorganisms play in the health and disease of the host's has been gaining prominence. This is a promising area with an increasing number of studies which demonstrates its importance. Conclusion: In this context, the new class of probiotic microorganisms "psychobiotic" appear to have a significant role in the maintenance of eubiosis, revealing a new therapeutic potential for mental health.

O objetivo do estudo foi avaliar a qualidade microbiologica de carnes de hamburguer comercializadas na cidade de Salvador, Bahia. Foram realizadas as analises microbiologicas: aerobios mesofilos, psicrotroficos, bolores e leveduras, coliformes 45 °C, Clostridium sulfito redutor, Staphylococcus sp e Salmonella sp, as analises foram realizadas segundo a metodologia descrita por Silva et al. (2017) e os resultados comparados com o padrao estabelecido pela RDC no 12/2001 da Agencia Nacional de Vigilância Sanitaria. Os resultados demonstram que as amostras estao de acordo com os parâmetros dispostos pela legislacao e nao oferecem risco a saude do consumidor do ponto de vista microbiologico.

The aim of this study was to evaluate the use of Maldi-Tof MS biosensor in microbial assessment of Brazilian kefir grains. Maldi-Tof MS is a new methodology for the rapid diagnosis of microorganisms. A total of 358 microorganisms were isolated, 31 were yeasts and 327 were bacteria (divided into lactic and acetic bacteria). Microbial colonies were grown in Luria-Bertani agar medium and incubated at 35 °C for 18h and used in the identification of species by Maldi-Tof MS. The microbial population identified in Brazilian kefir grains was Lactobacillus paracasei, Saccharomyces cerevisiae, Lactobacillus plantarum, Acetobacter pasteurianus, and Acetobacter syzygii. This study demonstrated a rapid and accurate identification of the Brazilian kefir grains microorganisms using the Maldi-Tof MS biosensor. In conclusion, the Maldi-Tof MS technology can facilitate the microbiological control in a fermentation process using kefir grains as starter cultures.

The aim of the present work was to evaluate the use of the sugary kefir grains as a starter culture for the production of a new quinoa-based (Chenopodium quinoa) kefir beverage flavored with cocoa (Theobroma cacao) powder. Fermentation was performed by inoculating kefir grains in quinoa extract and 5% brown sugar. Flasks containing kefir grains and substrates were statically incubated at 28 °C for 24 h. The microbiota of sugary kefir grains were genera Lactobacillus, Leuconostoc and Acetobacter, as well as yeasts Saccharomyces, Kluyveromyces, Lachancea and Kazachstania. After fermentation, the beverage was flavored with cocoa powder. The product was positively qualified by sensory analysis (~ 75% acceptance). This study is the first to report the production of quinoa-based kefir beverage. This result opens up perspectives for this innovative application of sugary kefir grains for developing cereal-based beverages.

Use of microbial systems for functional foods supplementation can be defined into fermentative process by starter cultures, use of probiotics microorganisms and use of microbial biomass. Scientific and technical aspects as related to use of microorganisms in functional foods supplementation are highly diverse and complex, since they have to deal with the viability of probiotic strains as well as with the safe production, nutritional composition and acceptability of the new product. However, limited information is available on the microorganisms which can be used in functional food supplements, as well as how to use these microorganisms and generation of products. This review reports details of this information. The data from this review can be useful to support the development of new functional products, with microbial supplementation, for the market. Key words: Kefir, yeast, microalgae, lactic acid bacteria, probiotic.

This study aims to characterize the physicochemical properties of cocoa’s residual honey and evaluate its fermentative capacity as a substrate, using Saccharomyces cerevisiae AWRI726 as the starter culture for alcoholic fermentation. The research hypothesis was that cocoa’s residual honey can be used for the production of fermented beverages. Cocoa’s honey has 14.14 g.100 mL−1 of dry material, containing 11.80 g.100 mL−1 of carbohydrates and 1.20% crude protein, in addition to other minor components, such as pectin, lipids, and Fe, Mn, Na, and Zn, with a carbon-to-nitrogen (C/N) ratio (9.8) most suitable for fermentation. Fermentation at 20°C for 240 hours produced a liquid with 16% v/v ethanol (14 g.L−1 in 144 h). However, 24 hours of fermentation produced the maximum ethanol yield (0.373 g.g−1) and volumetric productivity (0.168 g.L−1.h−1), which were associated with a significant increase in the specific cell growth rate. Saccharomyces cerevisiae AWR1726 performed satisfactorily in the alcoholic fermentation of cocoa’s residual honey, similar to that observed in other fruit beverages, thus suggesting the suitability of cocoa’s residual honey for future commercial applications.

Cell immobilization comprises the retention of metabolically active cells inside a polymeric matrix. In this study, the production of jabuticaba (Myrciaria jaboticaba) vinegar using immobilized Acetobacter aceti and Gluconobacter oxydans cells is proposed as a new method to prevent losses of jabuticaba fruit surplus. The pulp of jabuticaba was processed and Saccharomyces cerevisiae CCMA 0200 was used to ferment the must for jabuticaba wine production. Sugars, alcohols (ethanol and glycerol) and organic acids were assayed by high-performance liquid chromatography. Volatile compounds were determined by gas chromatography-flame ionization detector. The ethanol content of the produced jabuticaba wine was approx. 74.8 g/L (9.5 % by volume) after 168 h of fermentation. Acetic acid fermentation for vinegar production was performed using a mixed culture of immobilized A. aceti CCT 0190 and G. oxydans CCMA 0350 cells. The acetic acid yield was 74.4 % and productivity was 0.29 g/(L·h). The vinegar had particularly high concentrations of citric (6.67 g/L), malic (7.02 g/L) and succinic (5.60 g/L) acids. These organic acids give a suitable taste and flavour to the vinegar. Seventeen compounds (aldehydes, higher alcohols, terpene, acetate, diether, furans, acids, ketones and ethyl esters) were identified in the jabuticaba vinegar. In conclusion, vinegar was successfully produced from jabuticaba fruits using yeast and immobilized mixed cultures of A. aceti and G. oxydans. To the best of our knowledge, this is the first study to use mixed culture of immobilized cells for the production of jabuticaba vinegar.

The aim of this study was to develop a kefir apple-based vinegar and evaluate this fermentation process using new methodology with Biospeckle Laser. Brazilian kefir grains were inoculated in apple must for vinegar production. In this study, the microbial community present in kefir, and correspondent vinegar, was investigated using Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS) technique. Saccharomyces cerevisiae, Lactobacillus paracasei, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii were the microbial species identified. S. cerevisiae, L. plantarum, A. pasteurianus and A. syzygii were found in smaller quantities at the beginning of the alcoholic fermentation, but were found throughout the alcoholic and acetic fermentation. Kefir grains were able to utilize apple must as substrate to produce ethanol, and acetic acid. Acetate, volatile alcohols and aldehydes in the vinegar-based kefir were also produced. The yield of acetic acid in the kefir vinegars was ∼79%. The acetic acid concentration was ∼41 g L-1, reaching the required standard for the Brazilian legislation accepts it as vinegar (4.0% acetic acid). Kefir vinegar showed good acceptance in the sensory analysis. The technology proposed here is novel by the application of immobilized-cell biomass (kefir grains) providing a mixed inocula and eliminating the use of centrifuge at the end of the fermentative process. This step will save energy demand and investment. This is the first study to produce apple vinegar using kefir grains.

This work presents the biospeckle laser technique as a potential tool to analyse the kefir grains activity. In the present work, the kefir grains biological activity was measured from quantitative measurements by means of their speckle activity. The aim was to show that the biospeckle laser is a potential methodology to assess kefir grains viability, monitoring the kefir grains during the beverage production. The monitoring of the activity of the kefir is a key factor to guarantee the efficiency of the production of beverages, however the routine ways it is done compromise its use in the online production. The kefir grains were illuminated by a laser HeNe 17 mW 632 nm and analysed by the numerical biospeckle laser method. The results presented the statistical separation of the kefir in distinct levels of activity as expected. This can be an innovative technique to be used in the beverage industries for kefir grains inoculum control. Key words: Kefir, speckle activity, inoculum control.

A total of 307 yeasts strains were isolated from native Cerrado (Brazilian Savannah) soils collected at Passos, Luminarias and Arcos areas in Minas Gerais State, Brazil. The soils were chemically characterized. Ten yeast genera (Candida, Cryptococcus, Debaryomyces, Kazachstania, Kodamaea, Lindnera, Pichia, Schwanniomyces, Torulaspora and Trichosporon) and 23 species in both rainy and dry seasons were identified. All genera were abundant during the dry season. The pH values of the soil from the Passos, Luminarias and Arcos areas varied from 4.1 to 5.5. There were no significant differences in the concentrations of phosphorus, magnesium and organic matter in the soils among the studied areas. The Arcos area contained large amounts of aluminum during the rainy season and both hydrogen and aluminum in the rainy and dry seasons. The yeast populations identified seemed to be unaffected by the high levels of aluminum in the soil. The API ZYM® (BioMerieux, France) system was employed to characterize the extracellular enzymatic activity profiles of the yeast isolates. The results of the API ZYM® test showed differences in the extracellular enzyme profiles among the yeast species. Some isolates that belong to the same species showed enzymatic profiles that differed from one another. Our study is the first to describe yeasts isolated from Brazilian Cerrado soils from Minas Gerais State and demonstrates their ability to produce enzymes that may be of potential industrial interest. Key words: Enzymes, Brazilian soils, yeasts biodiversity, Cerrado.

This study describes the use of a nested PCR-denaturing gradient gel electrophoresis (DGGE) approach and scanning electron microscopy (SEM) to monitor the microbial diversity and distribution involved in spontaneous box fermentation of cocoa beans in Brazil. The nearly complete 16S rRNA and 18S rRNA genes were amplified using universal primers, and the resulting products were subsequently used as a template in a nested PCR to obtain suitable fragments for DGGE. Only two bands corresponding to the yeast species Saccharomyces cerevisiae and Hanseniaspora sp. were detected throughout the fermentation process. Sequencing of purified 16S rDNA amplicons indicated Lactobacillus plantarum, Lactobacillus fermentum and Acetobacter sp. to be the major bacterial groups during the fermentation course. Other partial 16S rDNA sequences corresponded to close relatives of Lactobacillus sp., Bacillus sp., Bacillus licheniformis, Bacillus firmus, Frateuria aurantia, Tatumella ptyseos, Xanthomonas sp. and an uncultured bacterium. SEM showed a well-defined microbial succession that was initially dominated by lemon-shaped yeast cells growing in close association with Lactobacillus (long and curved), and subsequently surpassed by short bacilli-shaped cells. This is the first report of SEM being used for following the microbial distribution during cocoa fermentation. Therefore, the nested PCR-DGGE and SEM techniques seem to offer a relatively fast and reliable method in monitoring microbial diversity and distribution during cocoa fermentation, providing real-time information and theory basis for the development of the starter.

Biochemical and molecular analysis was used for identification of different kefir yeasts species from Brazil, Canada and the United States of America. The sugar/ethanol-resistant activity of the yeasts was evaluated. Saccharomyces cerevisiae and Kluyveromyces marxianus had the highest growth rates, suggesting biotechnological applications possible for these strains.

Cell immobilization comprises the retention of metabolically active cells inside a polymeric matrix. In this study, the production of jabuticaba (Myrciaria jaboticaba) vinegar using immobilized Acetobacter aceti and Gluconobacter oxydans cells is proposed as a new method to prevent losses of jabuticaba fruit surplus. The pulp of jabuticaba was processed and Saccharomyces cerevisiae CCMA 0200 was used to ferment the must for jabuticaba wine production. Sugars, alcohols (ethanol and glycerol) and organic acids were assayed by high-performance liquid chromatography. Volatile compounds were determined by gas chromatography-flame ionization detector. The ethanol content of the produced jabuticaba wine was approx. 74.8 g/L (9.5% by volume) after 168 h of fermentation. Acetic acid fermentation for vinegar production was performed using a mixed culture of immobilized A. aceti CCT 0190 and G. oxydans CCMA 0350 cells. The acetic acid yield was 74.4% and productivity was 0.29 g/(L·h). The vinegar had particularly high concentrations of citric (6.67 g/L), malic (7.02 g/L) and succinic (5.60 g/L) acids. These organic acids give a suitable taste and flavour to the vinegar. Seventeen compounds (aldehydes, higher alcohols, terpene, acetate, diether, furans, acids, ketones and ethyl esters) were identified in the jabuticaba vinegar. In conclusion, vinegar was successfully produced from jabuticaba fruits using yeast and immobilized mixed cultures of A. aceti and G. oxydans. To the best of our knowledge, this is the first study to use mixed culture of immobilized cells for the production of jabuticaba vinegar.

Cell immobilization comprises the retention of metabolically active cells inside a polymeric matrix. In this study, the production of jabuticaba (Myrciaria jaboticaba) vinegar using immobilized Acetobacter aceti and Gluconobacter oxydans cells is proposed as a new method to prevent losses of jabuticaba fruit surplus. The pulp of jabuticaba was processed and Saccharomyces cerevisiae CCMA 0200 was used to ferment the must for jabuticaba wine production. Sugars, alcohols (ethanol and glycerol) and organic acids were assayed by high-performance liquid chromatography. Volatile compounds were determined by gas chromatography-flame ionization detector. The ethanol content of the produced jabuticaba wine was approx. 74.8 g/L (9.5 % by volume) after 168 h of fermentation. Acetic acid fermentation for vinegar production was performed using a mixed culture of immobilized A. aceti CCT 0190 and G. oxydans CCMA 0350 cells. The acetic acid yield was 74.4 % and productivity was 0.29 g/(L·h). The vinegar had particularly high concentrations of citric (6.67 g/L), malic (7.02 g/L) and succinic (5.60 g/L) acids. These organic acids give a suitable taste and flavour to the vinegar. Seventeen compounds (aldehydes, higher alcohols, terpene, acetate, diether, furans, acids, ketones and ethyl esters) were identified in the jabuticaba vinegar. In conclusion, vinegar was successfully produced from jabuticaba fruits using yeast and immobilized mixed cultures of A. aceti and G. oxydans. To the best of our knowledge, this is the first study to use mixed culture of immobilized cells for the production of jabuticaba vinegar., Imobilizacija stanica podrazumijeva zadržavanje metabolički aktivnih stanica unutar polimernog matriksa. U radu je predložena nova metoda proizvodnje octa iz plodova biljke Myrciaria jaboticaba pomoću imobiliziranih stanica bakterija Acetobacter aceti i Gluconobacter oxydans, za sprečavanje gubitaka u proizvodnji tog voća zbog viška plodova. Fermentacijom voćne pulpe pomoću kvasca Saccharomyces cerevisiae CCMA 0200 nastao je mošt, koji je zatim upotrijebljen za proizvodnju vina. Koncentracije šećera, alkohola (etanola i glicerola) i organskih kiselina u vinu određene su visokodjelotvornom tekućinskom kromatografijom, a koncentracije hlapljivih spojeva plinskom kromatografijom s plameno- -ionizacijskim detektorom. Koncentracija etanola u proizvedenom vinu bila je otprilike 74,8 g/L (volumni udjel 9,5 %) nakon 168 sati fermentacije. Pomoću mješovite kulture imobilizoranih stanica bakterija A. aceti CCT 0190 i G. oxydans CCM 0350 proizveden je ocat. Dobiven je prinos octene kiseline od 74,4 %, a produktivnost je postupka iznosila 0,29 g/(L·h). Proizvedeni ocat imao je izrazito velike koncentracije limunske (6,67 g/L), jabučne (7,02 g/L) i sukcinske kiseline (5,60 g/L). Te su mu organske kiseline dale prikladan okus i aromu. Identificirano je 17 različitih spojeva (aldehida, viših alkohola, terpena, acetata, dietera, furana, kiselina, ketona i etilnih estera) u octu. Zaključeno je da je ocat uspješno proizveden iz plodova biljke Myrciaria jaboticaba pomoću kvasca i imobilizirane mješovite kulture A. aceti i G. oxydans. Prema našim saznanjima, ovo je prvo istraživanje u kojem su za proizvodnju octa iz plodova biljke Myrciaria jaboticaba upotrebljene imobilizirane stanice mješovite kulture bakterija.

The aim of the present work was to evaluate the use of the kefir grains as a starter culture for new cocoa ( Theobroma cacao L.) beverages. Fermentation was performed by inoculating kefir grains in cocoa pulp. Flasks containing kefir grains and different substrates were statically incubated at 10 and 25 °C for 48 and 72 h. The microbiota of Brazilian kefir grains and kefir cocoa beverages was characterized using molecular techniques. Denaturing gradient gel electrophoresis displayed communities included yeasts: Kluyveromyces marxianus , Saccharomyces cerevisiae , Kazachstania unispora , and bacteria: Lactobacillus kefiranofaciens subsp. kefirgranum , Lactobacillus kefiranofaciens subsp. kefiranofaciens , Lactobacillus plantarum , Lactobacillus fermentum , and a bacterium related to the genus Acetobacter . A microbial steady structure was detected in the analyzed kefir cocoa beverages and kefir grains. This robustness is determinant for future implementation of cocoa-based kefir beverages. The lactic, acetic, malic, propionic and citric acid contents increased during the 72 h of fermentation process in kefir beverages, reaching maximum value of ~ 5.55 g L − 1 , ~ 1.0 g L − 1 , ~ 0.3 g L − 1 , ~ 1.0 g L − 1 and ~ 3.0 g L − 1 respectively. Oxalic, tartaric, butyric acids and glycerol were detected in similar concentrations. These compounds were found during the 48 and 72 h fermentation period at 10 and 25 °C in low concentration of ~ 1.4 g L − 1 . Methanol also was detected in low concentration of ~ 0.8 g L − 1 . The beverages fermented at 10 °C during 48 and 72 h produce lower amounts of ethanol ~ 4.5 g L − 1 (0.36% v/v). These beverages had the greater acceptance (92% and 100% of the panelist, respectively) based on taste, odor, and appearance of the beverages. The best acceptance may be due to low acidity/alcoholic concentration in the beverages. In this study it was possible to produce alcoholic kefir beverages (ethanol concentration of, ~ 45.0 g L − 1 (3.6% v/v)) with cocoa pulp fermentation for a period of 48 and 72 h at 25 °C. These beverages had acceptance by 80% of the panelist. This study is the first to report the alcoholic kefir beverage production from cocoa. Based on the chemical characteristics and acceptance in the sensory analysis, these results open up perspectives for this innovative application of kefir grains for developing cocoa pulp-based beverages.

Bacaba chicha is a beverage prepared by the indigenous Umutina people from the bacaba fruit (Oenocarpus bacaba), a purple berry that is rich in fat and carbohydrates, as well as a source of phenolic compounds. In this study, samples of bacaba chicha beverage were collected, and the microbial community was assessed using culture-dependent and -independent techniques. The nutritional composition and metabolite profiles were analyzed, and species belonging to lactic acid bacteria (LAB) and yeasts were detected. The LAB group detected by culture-dependent analysis included Enterococcus hormaechei and Leuconostoc lactis. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) detected additional Propionibacterium avidum, Acetobacter spp., and uncultured bacteria. Pichia caribbica and Pichia guilliermondii were detected in a culture-dependent method, and Pichia caribbica was confirmed by PCR-DGGE analysis. The pH value of the beverage was 6.2. The nutritional composition was as follows: 16.47 ± 0.73 g 100 mL-1 dry matter, 2.2 ± 0.0 g 100 mL-1 fat, 3.36 ± 0.44 g 100 mL-1 protein, and 10.87 ± 0.26 g 100 mL-1 carbohydrate. The metabolites detected were 2.69 g L-1 succinic acid, 0.9 g L-1 acetic acid, 0.49 g L-1 citric acid, 0.52 g L-1 ethanol, and 0.4 g L-1 glycerol. This is the first study to identify microbial diversity in bacaba chicha spontaneous fermentation. This study is also the starting step in the immaterial record of this Brazilian indigenous beverage prepared from bacaba fruit.

A total of 2152 Actinobacteria strains were isolated from native Cerrado (Brazilian Savannah) soils located in Passos, Luminárias, and Arcos municipalities (Minas Gerais State, Brazil). The soils were characterised for chemical and microbiological analysis. The microbial analysis led to the identification of nine genera (Streptomyces, Arthrobacter, Rhodococcus, Amycolatopsis, Microbacterium, Frankia, Leifsonia, Nakamurella,andKitasatospora) and 92 distinct species in both seasons studied (rainy and dry). The rainy season produced a high microbial population of all the aforementioned genera. The pH values of the soil samples from the Passos, Luminárias, and Arcos regions varied from 4.1 to 5.5. There were no significant differences in the concentrations of phosphorus, magnesium, and organic matter in the soils among the studied areas. Samples from the Arcos area contained large amounts of aluminium in the rainy season and both hydrogen and aluminium in the rainy and dry seasons. The Actinobacteria population seemed to be unaffected by the high levels of aluminium in the soil. Studies are being conducted to produce bioactive compounds from Actinobacteria fermentations on different substrates. The present data suggest that the number and diversity of Actinobacteria spp. in tropical soils represent a vast unexplored resource for the biotechnology of bioactives production.

This study used a multiphasic approach, characterized by the simultaneous use of culture-dependent and culture-independent methods, to investigate endophytic bacterial communities in strawberry (Fragaria ananassa) fruit. A total of 92 bacterial endophytes were isolated and initially grouped by their repetitive extragenic palindromic (rep)-PCR banding pattern and biochemical features. Phylogenetic analysis of the 16S rRNA gene sequences of 45 representatives showed that the isolates belonged to the species Bacillus subtilis (eight isolates), Bacillus sp. (seven isolates), Enterobacter sp. (seven isolates), Enterobacter ludwigii (six isolates), Lactobacillus plantarum (six isolates), Pseudomonas sp. (five isolates), Pantoea punctata (three isolates), and Curtobacterium citreum (three isolates). Nucleic acids were extracted from the strawberry fruit and subjected to 16S rRNA gene directed polymerase chain reaction denaturing gradient gel electrophoresis (16S rRNA PCR-DGGE). The species B. subtilis, Enterobacter sp., and Pseudomonas sp. were detected both by isolation and DGGE. The DGGE fingerprints of total bacterial DNA did not exhibit bands corresponding to several of the representative species isolated in the extinction dilution (L. plantarum, C. citreum, and P. punctata). In contrast, bands in the DGGE profile that were identified as relatives of Arthrobacter sp. and one uncultivable Erythrobacter sp. were not recovered by cultivation techniques. After isolation, the nitrogen fixation ability and the in vitro production of indole-3-acetic acid (IAA) equivalents and siderophores were evaluated. A high percentage of isolates were found to possess the ability to produce siderophores and IAA equivalents; however, only a few isolates belonging to the genera Pseudomonas and Enterobacter showed the ability to fix nitrogen. Plant growth promotion was evaluated under greenhouse conditions and revealed the ability of the Bacillus strains to enhance the number of leaves, shoot length, root dry weight, and shoot dry weight. The activity of the bacterial isolate identified as B. subtilis NA-108 exerted the greatest influence on strawberry growth and showed a 42.8% increase in number of leaves, 15.26% for high shoot, 43.5% increase in root dry weight, and a 77% increase in shoot dry weight when compared with untreated controls.

Microbial ecology and chemical composition of Brazilian kefir beverage was performed. The microorganisms associated with Brazilian kefir were investigated using a combination of phenotypic and genotypic methods. A total of 359 microbial isolates were identified. Lactic acid bacteria (60.5%) were the major isolated group identified, followed by yeasts (30.6%) and acetic acid bacteria (8.9%). Lactobacillus paracasei (89 isolates), Lactobacillus parabuchneri (41 isolates), Lactobacillus casei (32 isolates), Lactobacillus kefiri (31 isolates), Lactococcus lactis (24 isolates), Acetobacter lovaniensis (32 isolates), Kluyveromyces lactis (31 isolates), Kazachstania aerobia (23 isolates), Saccharomyces cerevisiae (41 isolates) and Lachancea meyersii (15 isolates) were the microbial species isolated. Scanning electron microscopy showed that the microbiota was dominated by bacilli (short and curved long) cells growing in close association with lemon-shaped yeasts cells. During the 24 h of fermentation, the protein content increased, while lactose and fat content decreased. The concentration of lactic acid ranged from 1.4 to 17.4 mg/ml, and that of acetic acid increased from 2.1 to 2.73 mg/ml. The production of ethanol was limited, reaching a final mean value of 0.5 mg/ml., The authors acknowledge Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) for scholarshipsand and CAARG - Cooperativa Agricola Alto Rio Grande Ltda. (Lavras/MG, Brazil) for the milk supply.

Whey valorization concerns have led to recent interest on the production of whey beverage simulating kefir. In this study, the structure and microbiota of Brazilian kefir grains and beverages obtained from milk and whole/deproteinised whey was characterized using microscopy and molecular techniques. The aim was to evaluate its stability and possible shift of probiotic bacteria to the beverages. Fluorescence staining in combination with Confocal Laser Scanning Microscopy showed distribution of yeasts in macro-clusters among the grain’s matrix essentially composed of polysaccharides (kefiran) and bacteria. Denaturing gradient gel electrophoresis displayed communities included yeast affiliated to Kluyveromyces marxianus, Saccharomyces cerevisiae, Kazachatania unispora, bacteria affiliated to Lactobacillus kefiranofaciens subsp. Kefirgranum, Lactobacillus kefiranofaciens subsp. Kefiranofaciens and an uncultured bacterium also related to the genus Lactobacillus. A steady structure and dominant microbiota, including probiotic bacteria, was detected in the analyzed kefir beverages and grains. This robustness is determinant for future implementation of whey-based kefir beverages., Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), CAPES-GRICES.

Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by kefir grains and compared with values obtained during the production of traditional milk kefir. The results showed that kefir grains were able to utilise lactose from CW and DCW and produce similar amounts of ethanol (7.8–8.3 g/l), lactic acid (5.0 g/l) and acetic acid (0.7 g/l) to those obtained during milk fermentation. In addition, the concentration of higher alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol, and 1-propanol), ester (ethyl acetate) and aldehyde (acetaldehyde) in cheese whey-based kefir and milk kefir beverages were also produced in similar amounts. Cheese whey and deproteinised cheese whey may therefore serve as substrates for the production of kefir-like beverages similar to milk kefir., The authors acknowledge the financial support from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), CAPES-GRICES and Lactogal for supplying cheese whey powder.

Submitted by Renorbio (renorbioba@ufba.br) on 2021-12-01T19:37:27Z No. of bitstreams: 1 Tese final - Andrea L Miranda.pdf: 2324806 bytes, checksum: 0f3e994c49e24787c27ee2ea82132475 (MD5) Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2021-12-20T16:08:43Z (GMT) No. of bitstreams: 1 Tese final - Andrea L Miranda.pdf: 2324806 bytes, checksum: 0f3e994c49e24787c27ee2ea82132475 (MD5) Made available in DSpace on 2021-12-20T16:08:43Z (GMT). No. of bitstreams: 1 Tese final - Andrea L Miranda.pdf: 2324806 bytes, checksum: 0f3e994c49e24787c27ee2ea82132475 (MD5) FAPESB A goma xantana é um exopolissacarídeo microbiano com várias funções nas Xanthomonas spp. e grande variedade de aplicações industriais devido a alta solubilidade em água, emulsibilidade, suspensibilidade e espessamento. Apesar da goma xantana ser um dos principais polissacarídeos de origem microbiana comercializados no mundo, apresenta ampla heterogeneidade na composição e massa molecular, e consequentemente nas propriedades resultantes. Dessa maneira, nesse estudo foi investigada a composição de ácidos graxos celulares e o efeito de diferentes cepas e tempo de cultivo de Xanthomonas spp. com a finalidade de identificar marcadores de produção, composição e qualidade das gomas xantanas obtidas. As cepas de Xanthomonas axonopodis pv. manihotis 290, Xanthomonas campestris pv. mangiferaeindicae 645 e Xanthomonas campestris pv. campestris 1155 foram monitoradas durante 168 h de cultivo. A cada 24 horas, amostras de células e das gomas foram avaliadas por meio das análises de FTIR, DRX, viscosidade aparente, massa molecular, TGA, açúcares e ácidos, além da determinação do crescimento celular e consumo do substrato. As três cepas de Xanthomonas spp. apresentaram perfis qualitativos de ácidos graxos celulares semelhantes durante todo o cultivo, sendo os ácidos 16: 1n7 e 16: 0 os majoritários. Para todas as cepas estudadas, foram obtidas correlações significativas entre as razões desses ácidos graxos e as produções de goma xantana. Constatou-se também influência das características intrínsecas das cepas nas propriedades, produção e composição do polímero. A cepa X. campestris pv. campestris 1155 apresentou maior produtividade em 24 horas de cultivo (0,149 g L-1 h-1), mas com propriedades limitadas para aplicação industrial, tais como viscosidade e massa molecular. Por outro lado, a cepa Xanthomonas axonopodis pv. manihotis 290 apresentou comportamento inverso, porém, com maior produtividade apenas após 96h (0,039 g L-1 h-1). Não houve associação direta entre a composição de ácidos graxos e as propriedades das gomas sintetizadas. Com base na avaliação de alguns parâmetros cinéticos do cultivo, foi possível definir a cepa de Xanthomonas (290) e o tempo de cultivo (48h), associados a qualidade do exopolimero resultante. Pela primeira vez foi identicada uma relação direta entre ácidos graxos insaturados / saturados (I/S) celulares e a produção da goma xantana, o que permite a identificação de um possível marcador químico de produção desse biopolímero. Xanthan gum is a microbial exopolysaccharide with various functions in Xanthomonas spp. and a wide variety of industrial applications due to its high water solubility, emulsifiability, suspensibility and thickening. Although xanthan gum is one of the main polysaccharides of microbial origin marketed worldwide, it presents wide heterogeneity in composition and molecular mass, and consequently in the resulting properties. In this way, this study investigated the composition of cell fatty acids and the effect of different strains of Xanthomonas spp. and time culture with the purpose of identifying production markers, composition and quality of xanthan gums obtained. Xanthomonas axonopodis pv. manihotis 290, Xanthomonas campestris pv. mangiferaeindicae 645 and Xanthomonas campestris pv. campestris 1155 strains were monitored for 168h of culture. At 24h, cell and gum samples were analyzed by FTIR, XRD, apparent viscosity, molecular mass, TGA, sugars and acids, as well as determination of cell growth and substrate consumption. The three Xanthomonas spp. strains presented qualitative profiles of cellular fatty acids similar throughout the culture, with the acids 16: 1n7 and 16: 0 being the major ones. For all strains studied, significant correlations were obtained between the ratios of these fatty acids and xanthan gum production. It was also verified the influence of the intrinsic characteristics of the strains on the properties, production and composition of the polymer. The strain X. campestris pv. campestris 1155 showed higher productivity in 24 hours of cultivation (0.149 g L-1 h-1) but with limited properties for industrial application such as viscosity and molecular mass. On the other hand, the strain Xanthomonas axonopodis pv. manihotis 290 presented an inverse behavior, however, with higher productivity only after 96h (0.039 g L-1 h-1). There was not direct association between the composition of fatty acids and the synthesized gums properties. Based on the evaluation of some kinetic parameters of the culture, it was possible to define the Xanthomonas strain (290) and the culture time (48h), associated with the quality of the resulting exopolymer. For the first time, a direct relationship between unsaturated / saturated cellular fatty acids (U / S) and the xanthan gum production was identified, which allows the identification of a possible chemical marker of production of this biopolymer.