Production of ethanol from mesquite (Prosopis juliflora (SW) D.C.) pods mash by Zymomonas mobilis and Saccharomyces cerevisiae

This study aimed to assess the use of mesquite pods hydrated mash as biomass for the growth of Saccharomyces cerevisiae UFEPEDA-1012 and Zymomonas mobilis UFEPEDA-205 and for ethanol production using a submerged fermentation. A 2³ factorial design was used to analyze the effects of the type of microorganism, time of fermentation and condition of cultivation on the ethanol production in mesquite pods mash (30 g 100 mL-1). From the obtained results the hydrated mesquite pods mash presented as a good substrate for the growth of S. cerevisiae and Z. mobilis in comparison to the standard media. The effect that most affected the ethanol production was the type of microorganism. The highest ethanol concentration (141.1 gL-1) was found when Z. mobilis was cultivated in mesquite pods mash under static condition for 36 hrs. Ethanol production by S. cerevisiae was higher (44.32 gL-1) after 18 hrs of fermentation under static condition. According to these results, the mesquite pods could be known as an alternative substrate to be used for biotechnological purposes, mainly for ethanol production

Analysis of 16S rRNA and mxaF genes reveling insights into Methylobacterium niche-specific plant association

The genus Methylobacterium comprises pink-pigmented facultative methylotrophic (PPFM) bacteria, known to be an important plant-associated bacterial group. Species of this group, described as plant-nodulating, have the dual capacity of producing cytokinin and enzymes, such as pectinase and cellulase, involved in systemic resistance induction and nitrogen fixation under specific plant environmental conditions. The aim hereby was to evaluate the phylogenetic distribution of Methylobacterium spp. isolates from different host plants. Thus, a comparative analysis between sequences from structural (16S rRNA) and functional mxaF (which codifies for a subunit of the enzyme methanol dehydrogenase) ubiquitous genes, was undertaken. Notably, some Methylobacterium spp. isolates are generalists through colonizing more than one host plant, whereas others are exclusively found in certain specific plant-species. Congruency between phylogeny and specific host inhabitance was higher in the mxaF gene than in the 16S rRNA, a possible indication of function-based selection in this niche. Therefore, in a first stage, plant colonization by Methylobacterium spp. could represent generalist behavior, possibly related to microbial competition and adaptation to a plant environment. Otherwise, niche-specific colonization is apparently impelled by the host plant

Antimicrobial activity and phytochemical screening of buchenavia tetraphylla (aubl.) R. A. Howard (combretaceae: combretoideae)

This study evaluated the antimicrobial and hemolytic activities and phytochemical constituents of hydroalcoholic extract and its fractions from Buchenavia tetraphylla leaves. Cyclohexane (BTCF), ethyl acetate (BTEF), and n-butanol-soluble (BTSBF) and non-soluble (BTNBF) fractions were obtained from a liquid-liquid partition of hydroalcoholic extract (BTHE) from B. tetraphylla leaves. The hemolytic activity of active fractions was checked. The BTHE inhibited the growth of Micrococcus luteus (MIC: 0.10 mg/mL), Pseudomonas aeruginosa (MIC: 0.20 mg/mL), Mycobacterium smegmatis (MIC: 0.39 mg/mL), Proteus vulgaris, and Staphylococcus aureus(MIC: 0.78 mg/mL for both). The more active fractions were BTCF and BTBSF. BTCF showed better potential to inhibit M. luteus (0.10 mg/mL), P. aeruginosa (0.20 mg/mL), S. enteritidis (0.39 mg/mL), and S. aureus (1.56 mg/mL). BTBSF showed the best results for M. luteus (0.10 mg/mL), M. smegmatis, B. subtilis (0.39 mg/mL for both), and P. vulgaris (0.10 mg/mL). The HC50 were greater than observed MIC: 20.30, 4.70 and 2.53 mg/mL, respectively, to BTBF, BTHE and BTCF, which. The phytochemical analysis detected the presence of flavanoids, triterpene, carbohydrate, and tannin. Our work showed for the first time the broad-spread antimicrobial activity of B. tetraphylla, which has nonhemolytic action, creating a new perspective on the interesting association of traditional and scientific knowledge

Síntese e avaliação da atividade antimicrobiana de novas 4-tiazolidinonas obtidas a partir de formilpiridina tiossemicarbazonas

Twelve novel 4-thiazolidinone derivatives (2a-l) have been synthesized by reacting formilpyridine thiosemicarbazones (1a-l) and anhydride maleic in toluene. Their chemical structures were confirmed by IR, ¹H and 13C NMR. The new compounds were submitted to in vitro evaluation against pathogenic Gram-positive, Gram-negative bacteria and yeasts. The findings obtained showed that the compounds 2a, 2d, 2e and 2g were effective against some of the bacterial strains used, whereas the compounds 2d, 2e and 2i exhibited a moderate antifungal activity against the yeast strains evaluated. An initial structure activity relationship (SAR) was established

Conjugative plasmids and protoplast fusion in Streptomyces felleus

Diferentes espécies de Streptomyces, isoladas de amostras de solo do Estado de Pernambuco, mostraram-se produtoras de actinomicina, apresentando formação de pigmento solúvel amarelo-laranja, uma característica de linhagens produtoras desse antibiótico. Três dessas espécies foram ensaiadas em diferentes concentrações de acriflavina e revelaram elevada instabilidade na produção de actinomicina. Em Streptomyces felleus IA-M3079 os mutantes antibiótico-negativos obtidos através do tratamento com o agente intercalante mostraram incialmente um único tipo morfológico, enquanto que os mutantes antibiótico-negativos de S. regensis IA-M3053 apresentaram diferentes características fenotípicas. Foram, também, observadas variantes de S. felleus IA-M3079 com produção de pigmento amarelo-laranja mais intenso que o das linhagens selvagens. As variantes de S. regensis IA-M3053 mostraram-se estáveis para esta característica e as S. felleus IA-M3079 eram instáveis, vindo a desaparecer o pigmento após algumas transferências. Contudo, entre as variantes de S. felleus IA-M3079 destacou-se uma estável com intensa pigmentação. Foi observada, através do fenótipo pock, nas três linhagens em estudo - S. felleus IA-M3079, S. parvulus IA-M3042 e S. regensis IA-M3053 a presença de plasmídios conjugados. A fusão de protoplastos entre S. felleus IA-M3079 e a variante AF-3079 (90/57) mostrou setores recombinantes com formação de pigmento azul-violáceo, que após estabilização e testes antimicrobianos apresentaram elevada atividade antifúngica. As culturas estabilizadas provenientes dos referidos setores segregantes, mostraram estreita similaridade com as parentais quanto às características bioquímicas, micromorfológicas e culturais e ao comportamento eletroforético. O antifúngico produzido pelos setores foi preliminarmente caracterizado através do espectro de absorção na luz ultravioleta.Different Streptomyces species, isolated from soil samples of Pernambuco State, Brazil, produce actinomycin and present the formation of yellow-orange solube pigment: a characteristic of strains producing that antibiotic. Three Streptomyces species were tested in different concentrations of acriflavine and showed high instability in the actinomycin production. In Streptomyces felleus IA-M3079, the negative antibiotic mutants obtained through the treatment with the intercalant agent showed a single morphology type, the negative antibiotic mutants of S. regensis IA-M3053 presented different phenotypical features. Besides, it were observed variants of S. felleus IA-M3079 with yellowish-orange pigment production more intensive than that of the wild strains. The S. regensis IA-M3053 variants showed themselves stable for this character and the S. felleus IA-M3079 variants were unstable, disappearing its pigment after some subcultivation. However,among the S. felleus IA-M3079 variants one appeared with intensive and stable pigment. Through the pock phenotype it was observed the presence of conjugative plasmids in the three strains under study: S. felleus IA-M3079, S. parvulus IA-M3042 and S. regensis IA-M3053. The protoplast fusion between S. felleus IA-M3079 and the variant AF-3079 (90/57) produced recombinant sectors with formation of bluish violaceous pigment. Such sectors, after stabilization and antimicrobial tests present high antifungal activity. The purified and stabilized cultures obtained from the recombinant sector showed to be very similar to the parental cultures regarding to biochemical, micromorphological and cultural characteristics as well as to the electrophoretical patterns. The antifugal compound produced by the sector recombinant cultures was characterized through ultraviolet spectra (UV) and by antimicrobial spectra

Conjugative plasmids and protoplast fusion in Streptomyces felleus

Diferentes espécies de Streptomyces, isoladas de amostras de solo do Estado de Pernambuco, mostraram-se produtoras de actinomicina, apresentando formação de pigmento solúvel amarelo-laranja, uma característica de linhagens produtoras desse antibiótico. Três dessas espécies foram ensaiadas em diferentes concentrações de acriflavina e revelaram elevada instabilidade na produção de actinomicina. Em Streptomyces felleus IA-M3079 os mutantes antibiótico-negativos obtidos através do tratamento com o agente intercalante mostraram incialmente um único tipo morfológico, enquanto que os mutantes antibiótico-negativos de S. regensis IA-M3053 apresentaram diferentes características fenotípicas. Foram, também, observadas variantes de S. felleus IA-M3079 com produção de pigmento amarelo-laranja mais intenso que o das linhagens selvagens. As variantes de S. regensis IA-M3053 mostraram-se estáveis para esta característica e as S. felleus IA-M3079 eram instáveis, vindo a desaparecer o pigmento após algumas transferências. Contudo, entre as variantes de S. felleus IA-M3079 destacou-se uma estável com intensa pigmentação. Foi observada, através do fenótipo pock, nas três linhagens em estudo - S. felleus IA-M3079, S. parvulus IA-M3042 e S. regensis IA-M3053 a presença de plasmídios conjugados. A fusão de protoplastos entre S. felleus IA-M3079 e a variante AF-3079 (90/57) mostrou setores recombinantes com formação de pigmento azul-violáceo, que após estabilização e testes antimicrobianos apresentaram elevada atividade antifúngica. As culturas estabilizadas provenientes dos referidos setores segregantes, mostraram estreita similaridade com as parentais quanto às características bioquímicas, micromorfológicas e culturais e ao comportamento eletroforético. O antifúngico produzido pelos setores foi preliminarmente caracterizado através do espectro de absorção na luz ultravioleta.Different Streptomyces species, isolated from soil samples of Pernambuco State, Brazil, produce actinomycin and present the formation of yellow-orange solube pigment: a characteristic of strains producing that antibiotic. Three Streptomyces species were tested in different concentrations of acriflavine and showed high instability in the actinomycin production. In Streptomyces felleus IA-M3079, the negative antibiotic mutants obtained through the treatment with the intercalant agent showed a single morphology type, the negative antibiotic mutants of S. regensis IA-M3053 presented different phenotypical features. Besides, it were observed variants of S. felleus IA-M3079 with yellowish-orange pigment production more intensive than that of the wild strains. The S. regensis IA-M3053 variants showed themselves stable for this character and the S. felleus IA-M3079 variants were unstable, disappearing its pigment after some subcultivation. However,among the S. felleus IA-M3079 variants one appeared with intensive and stable pigment. Through the pock phenotype it was observed the presence of conjugative plasmids in the three strains under study: S. felleus IA-M3079, S. parvulus IA-M3042 and S. regensis IA-M3053. The protoplast fusion between S. felleus IA-M3079 and the variant AF-3079 (90/57) produced recombinant sectors with formation of bluish violaceous pigment. Such sectors, after stabilization and antimicrobial tests present high antifungal activity. The purified and stabilized cultures obtained from the recombinant sector showed to be very similar to the parental cultures regarding to biochemical, micromorphological and cultural characteristics as well as to the electrophoretical patterns. The antifugal compound produced by the sector recombinant cultures was characterized through ultraviolet spectra (UV) and by antimicrobial spectra

Genetic variability in regenerated Metarhizium flavoviride protoplasts

Protoplast isolation and regeneration were evaluated in two wild-type and two colour mutant strains of Metarhizium flavoviride. Cultivation in liquid medium, followed by mycelium treatment with Novozym 234 in the presence of KCl 0.7M as osmotic stabilizer, produced 5.05 x 10(6) to 1.15 x 10(7)x mL-1 protoplasts. The percentage of regeneration ranged from 6.65 to 27.92%. Following protoplast regeneration, one strain produced spontaneously stable morphological variant colonies. Although colonies with altered morphology have been reported in bacteria following protoplast regeneration, this is the first time that the same is described in a filamentous fungus. The original strain and one derived variant were tested for sensitivity to the fungicides benomyl and captan.<br>A formação e regeneração de protoplastos foram avaliadas em duas linhagens selvagens e duas linhagens mutantes para coloração de conídios em Metarhizium flavoviride. O cultivo em meio líquido seguido do tratamento do micélio com Novozym 234 na presença de KCl 0,7 M como estabilizador osmótico, resultou na produção de 5,05´10(6) a 1,15´10(7) protoplastos´mL-1. A porcentagem de regeneração das diferentes linhagens variou de 6,65 a 27,92%. Após a regeneração, uma das linhagens selvagens produziu espontaneamente variantes estáveis, com morfologia alterada. Embora variantes morfológicos já tenham sido observados após regeneração de protoplastos em bactérias, esta parece ser a primeira vez que tal ocorrência é descrita em fungos filamentosos. Um desses variantes, além da linhagem selvagem da qual ele foi originado, foi testado para sensibilidade aos fungicidas benomil e captano

Seleção de bacillus spp. para produção de esterases e melhoramento de bacillus cereus (c124) Selection of bacillus spp. For esterase production and genetic improvement of bacillus cereus (c124)

Forty-four Bacillus spp. strains obtained from sugar cane derivates and residues, six of them isolated in this work, were tested using Tween 80 as substrate (agar-Tween 80 medium), in order to determine their esterase activity through the enzymatic index averages. After statistic analysis, B. cereus (C124) strain, which presented better results, was submitted to genetic improvement by treatment with ultraviolet light (UV). The survival curve pointed out 28" as the time necessary to obtain 30% of survivors. Fifty survivors and the wild strain C124 were compared in relation to their esterase activity as mentioned previously. The wild strain and the mutant C124UV35, which showed enzymatic index average higher than C124, were characterized in polyacrilamide gel electrophoresis (PAGE). Eletrophoretic patterns for total proteins of wild and mutant strain showed different profiles according to number, position and intensity of bands. For esterase, the bands varied only in intensity