Fermentation Enhanced Biotransformation of Compounds in the Kernel of Chrysophyllum albidum.

Chrysophyllum albidum Linn (African star apple) is a fruit with extensive nutritional and medicinal benefits. The fruit and kernel in the seed are both edible. Strains of lactic acid bacteria (LAB) were isolated from fermented seeds and assessed for probiotic characteristics. The extracts in both the unfermented and the fermented aqueous extracts from the kernels obtained from the seeds of C. albidum were subjected to analysis using the gas chromatography/mass spectrometry (GC-MS) method. This analysis identified the bioactive compounds present as possible substrate(s) for the associated organisms inducing the fermentation and the resultant biotransformed products formed. Three potential probiotic LAB strains identified as Lactococcus raffinolactis (ProbtA1), Lactococcus lactis (ProbtA2a), and Pediococcus pentosaceus (ProbtA2b) were isolated from the fermented C. albidum seeds. All strains were non hemolytic, which indicated their safety, Probt (A1, A2a, and A2b) grew in an acidic environment (pH 3.5) during the 48-h incubation time, and all three strains grew in 1% bile, and exhibited good hydrophobicity and auto-aggregation properties. Mucin binding proteins was not detected in any strain, and bile salt hydrolase was detected in all the strains. l-lactic acid (28.57%), norharman (5.07%), formyl 7E-hexadecenoate (1.73%), and indole (1.51%) were the four major constituents of the fermented kernel of the C. albidum, while 2,5-dimethylpyrazine (C1, 1.27%), 3,5-dihydroxy-6-methyl-2,3-dihydropyran-4-one (C2, 2.90%), indole (C3, 1.31%), norharman (C4, 3.01%), and methyl petroselinate (C5, 4.33%) were the five major constituents of the unfermented kernels. The isolated LAB are safe for consumption. The fermenting process metabolized C1, C2, and C5, which are possible starter cultures for the growth of probiotics. Fermentation is an essential tool for bioengineering molecules in foods into safe and health beneficial products.

Unveiling the Microbiota Diversity of the Xerophyte Argania spinosa L. Skeels Root System and Residuesphere.

The microbiota associated to xerophyte is a "black box" that might include microbes involved in plant adaptation to the extreme conditions that characterize their habitat, like water shortage. In this work, we studied the bacterial communities inhabiting the root system of Argania spinosa L. Skeels, a tree of high economic value and ecological relevance in Northern Africa. Illumina 16S rRNA gene sequencing and cultivation techniques were applied to unravel the bacterial microbiota's structure in environmental niches associated to argan plants (i.e., root endosphere, rhizosphere, root-surrounding soil), not associated to the plant (i.e., bulk soil), and indirectly influenced by the plant being partially composed by its leafy residue and the associated microbes (i.e., residuesphere). Illumina dataset indicated that the root system portions of A. spinosa hosted different bacterial communities according to their degree of association with the plant, enriching for taxa typical of the plant microbiome. Similar alpha- and beta-diversity trends were observed for the total microbiota and its cultivable fraction, which included 371 isolates. In particular, the residuesphere was the niche with the highest bacterial diversity. The Plant Growth Promotion (PGP) potential of 219 isolates was investigated in vitro, assessing several traits related to biofertilization and biocontrol, besides the production of exopolysaccharides. Most of the multivalent isolates showing the higher PGP score were identified in the residuesphere, suggesting it as a habitat that favor their proliferation. We hypothesized that these bacteria can contribute, in partnership with the argan root system, to the litter effect played by this tree in its native arid lands.

Phytochemistry and antibacterial activity of aqueous andhydroalcoholic extracts of three medicinal plants against foodpathogens / Fitoquímica e atividade antibacteriana de extratos aquosos e hidroalcoólicos de trêsplantas medicinais contra patógenos de alimentos

This study aimed to characterize the phytochemical compositions of three medicinal Brazilian plants’ leaves and bast extracts, and to determine their antibacterial activity on three foodborne and waterborne bacterial pathogens. Parkia platycephala, Pouteria ramiflora and Lophanthera lactescens leaves and basts were collected and aqueous and hydroalcoholic extracts were prepared. Qualitative screening of the phytochemical extracts was performed with three replicates and in triplicate in order to identify the bioactive compounds. The Minimal Inhibitory Concentration and Minimal Bactericide Concentration were determined by microdilution in broth and Escherichia coli, Salmonella typhimurium and Staphylococcus aureus growth was observed on agar plates. Phytochemical composition analysis allowed for the identification of anthraquinones, catechins, saponins, tannins, sesquiterpenlactones and other lactones in the three plants’ leaves and bast aqueous and hydroalcoholic extracts. Eighty-three percent of the plant extracts showed antibacterial activity against S. aureus, and P. platycephala extracts were the only ones that inhibited E. coli and S. typhimurium growth. The present study contributes significantly to the phytochemical composition characterization of three plant species commonly used in Brazilian traditional medicine. The plant extracts’ in vitro antibacterial activity was demonstrated and catechins present in the extracts are, most likely, the bioactive compounds responsible for this action.

Este estudo objetivou caracterizar a composição fitoquímica dos extratos de folhas e das entrecascas de três plantas medicinais brasileiras e determinar a sua atividade antimicrobiana contra três patógenos bacterianos de alimentos. Foram elaborados extratos aquosos e hidroalcoólicos, por meio de folhas e de entrecascas de Parkiaplatycephala, Pouteriaramiflora e Lophantheralactescens. O estudo qualitativo dos extratos foi realizado com três réplicas, em triplicata, para permitir a identificação dos compostos bioativos. A Concentração Inibitória Mínima e a Concentração Bactericida Mínima foram determinadas por microdiluição contra Escherichia coli, Salmonella typhimurium e Staphylococcus aureus. A análise da composição fitoquímica permitiu identificar antraquinonas, catequinas, saponinas, taninas, sesquiterpenlactonas e outras lactonas nos extratos aquosos e hidroalcoólicos das folhas e das entrecascas das três plantas. Oitenta e três porcento dos extratos das plantas apresentaram atividade antibacteriana contra S. aureus. Os extratos de P. platycephala foram os únicos que inibiram o crescimento de E. coli e S. typhimurium. Este estudo contribui significativamente para a caracterização da composição fitoquímica de três espécies de plantas, frequentemente, utilizadas na medicina tradicional brasileira. A atividade antibacteriana, in vitro, dos extratos das plantas foi demonstrada, e as catequinas são, provavelmente, o composto bioativo responsável por essa atividade.

Streptomyces marokkonensis sp. nov., isolated from rhizosphere soil of Argania spinosa L.

The novel actinomycete strain Ap1(T) was isolated from rhizosphere soil of the argan tree (Argania spinosa L.) in the south of Morocco. Strain Ap1(T) has been reported as a novel producer of the pentaene polyene macrolide isochainin, which strongly inhibits the growth of pathogenic yeasts and phytopathogenic fungi. Strain Ap1(T) shows a greyish-white aerial mycelium with chains of smooth-surfaced spores of the Spiralis type and a cell wall containing ll-diaminopimelic acid. Based on chemotaxonomy and morphological features, strain Ap1(T) was identified as a member of the genus Streptomyces. 16S rRNA gene sequence similarities based on almost-complete 16S rRNA gene sequences showed that strain Ap1(T) is closely associated with members of the Streptomyces violaceoruber species group (S. violaceoruber, S. coelescens, S. violaceorubidus, 'S. caesius', 'S. lividans', S. violaceolatus and S. humiferus) and others (Streptomyces aurantiogriseus, S. lienomycini, S. chattanoogensis, S. rubrogriseus and S. tendae). However, protein profiling, DNA-DNA hybridization and BOX-PCR fingerprinting proved a relationship above the species level. In addition, the phenotype also allowed for the differentiation of strain Ap1(T) from its closest neighbours. As a result of this polyphasic approach, we conclude that strain Ap1(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces marokkonensis sp. nov. is proposed. The type strain is Ap1(T) (=R-22003(T) =LMG 23016(T) =DSM 41918(T)).