<b>Enzymatic and antagonistic potential of bacteria isolated from typical fruit of Cerrado in Minas Gerais State, Brazil

Abstract

ABSTRACT. Brazil has great biodiversity, which is observed in the Cerrado biome of the tropical Brazilian savanna. The objectives of this study were to isolate and identify bacteria from Psychotria hoffmannseggiana with potential cellulase and pectinase production and with antagonistic activity against Aspergillus carbonarius, an Ochratoxin A (OTA) producer. Ripe fruit were collected in the region of Passos City in the preserved Cerrado area in Minas Gerais State, Brazil. Serial dilutions were performed, and the bacteria isolated were biochemically characterized and identified by sequencing. To analyze the production of enzymes, the bacteria were cultivated in CMC and pectinase media. The better enzyme producers were optimized for production. Assays on the antagonistic activity for growth and sporulation were carried out in co-culture (bacteria and filamentous fungi). TLC was performed to verify the mycotoxin production. The predominant microbiota were Gram-negative bacteria belonging to the Enterobacteriaceae family. Some isolates showed potential for enzymatic and antagonistic activity, especially the isolate identified as Lysinibacillus fusiformis. This species was a better producer of cellulases (maximum activity: 103.1 mg glucose min.-1 mg -1 protein). In conclusion, the bacteria isolated from Psychotria hoffmannseggiana showed biotechnological potential for agro-industry and the environmental aspect.Keywords: microorganism, Psychotria hoffmannseggiana, biotechnological application.Potencial enzimático e antagonista de bactérias isoladas de fruto típico do Cerrado em Minas Gerais, Brasil RESUMO. O Brasil tem uma grande biodiversidade no bioma Cerrado típico de savanas tropicais. Os objetivos deste estudo foram isolar e identificar bactérias celulolíticas e pectinolíticas e com atividade antagonista contra contra Aspergillus. carbonarius produtores de ocratoxina a partir de Psychotria hoffmannseggiana. Frutos maduros de P. hoffmannseggiana foram coletadas na região da cidade de Passos em área preservada de Cerrado em Minas Gerais, Brasil. Realizou-se diluições decimais e as bactérias isoladas foram caracterizados bioquimicamente e identificadas por seqüenciamento. Para a produção de enzimas, as bactérias foram cultivadas em CMC e MP5 e MP7. Os isolados com melhor produção enzimática foram submetidos ao processo de otimização. A atividade antagonista foi realizada em co-cultura (bactérias e fungos filamentosos) e avaliou-se o crescimento e a esporulação. TLC foram realizados para verificar a produção de micotoxinas. A microbiota predominante foi Gram negativas pertencem à família Enterobacteriaceae. Alguns isolados apresentaram potencial para a atividade enzimática e antagonista, especialmente o isolado identificado como Lysinibacillus fusiformis. Esta espécie foi melhor produtora de celulases (atividade máxima 103,1 mg glicose min.-1 mg -1 de proteína). Três dos 105 isolados de bactérias estimularam a produção de micotoxinas. Conclui-se que estes isolados apresentam potencial biotecnológico para a área de ag...

Evaluation of the biocontrol potential of endophytic bacteria isolated from Coffea liberica (w. Bull ex hiern) against brown eyespot-causing fungal phytopathogen

“…Positive activities of HCC10 -1 SC1 and ICC10 -3 SC1 in the cellulolytic enzyme assay confirmed the ability of these bacteria to hydrolyze the cellulose and other polysaccharides (Muñoz et al, 2014) resulting in fungal antagonism. The positive activities in the enzymatic assays confirmed the antifungal properties of the top five performing endophytic bacterial isolates (Silva et al, 2015).…”

“…After homogenizing, the mixture was plated onto a trypticase soy agar (TSA) for each dilution (10 -1 , 10 -2 and 10 -3 ) and incubated at 37 ºC for 24 h. The bacterial colonies on the mixed plate were selected according to their morphology (size, color, shape) and sub-cultured by quadrant streak method. A stock culture was made in tryptic soy broth (TSB) consisting of 17 g tryptone, 3 g soytone, 2.5 glucose, 5 g sodium chloride (NaCl), 2.5 g dipotassium phosphate and incubated at 37 ºC for 24 h. A 15% glycerol was added, and the cultures were maintained in the freezer at -20°C (Costa et al, 2012;Silva et al, 2015).…”

Assessment of morphophysiological and genotypic diversity of endophytic bacteria isolated from rice (Oryza sativa L.) plants

“…According to Lupo, Coyne and Berendonk (2012), an intrinsic antibiotic resistance of microorganisms allows them to successfully survive in the soil and colonize plants. The production of hydrolytic enzymes, such as amylases, cellulases, chitinases, proteases, and pectinases, is involved in the pathogen control process, assisting bacteria to penetrate plant tissue and access energy sources (SZILAGYI-ZECCHIN et al, 2014;SILVA et al, 2015). Phosphate solubilization also contributes to the biological control of some fungal species (DINESH et al, 2015).…”

Impact of processing, packages, and storage on quality of mangaba ( Hancornia speciosa Gomes) jelly

“…The Cerrado biome presents a huge variety of native species, whose exotic fruit has great potential because of their functional properties and nutritional value, as well as their pleasant and even exotic sensory traits, such as color, flavor, and aroma (Almeida et al., 2019; Silva et al., 2015).…”