Isolation and Characterization of a New Ferulic-Acid-Biotransforming Bacillus megaterium from Maize Alkaline Wastewater (Nejayote).

Nejayote is an alkaline wastewater generated during the nixtamalization process. Nejayote contains high-value compounds such as ferulic acid (FA), which is widely employed as a substrate for the biotechnological production of flavors and aromas. In the present study, the isolation, identification, and characterization of a native strain of Bacillus megaterium were performed, and its capacity to produce 4-vinylguaiacol (4VG) from ferulic acid was evaluated by employing growing cell and resting cell systems. Growing cells of native B. megaterium biotransformed 6 mM crude FA in nejayote into 2.1 mM 4VG, reaching a productivity of 0.21 mM h-1 4VG, while nejayote enriched with FA at 10, 15, and 25 mM resulted in the formation of 2.4, 3.8, and 6.2 mM 4VG and productivities of 0.24, 0.38, and 0.51 mM h-1 4VG, respectively. In the resting cell system, from 6 and 25 mM pure FA, 3.5 mM 4VG was produced (0.18 mM h-1 4VG), while at 10 and 15 mM FA, 4.6 and 5.1 mM 4VG (average of 0.24 mM h-1 4VG) were obtained, respectively. The native B. megaterium strain, isolated from nejayote, showed great biotechnological potential to produce 4VG from crude FA contained in this wastewater, in which other Bacillus species, such as B. licheniformis and B. cereus, were unable to grow and biotransform FA into 4VG.

Proteomic response of Saccharomyces boulardii to simulated gastrointestinal conditions and encapsulation.

Probiotics are live microorganisms conferring health benefits when administered in adequate amounts. However, the passage through the gastrointestinal tract represents a challenge due to pH variations, proteases, and bile salts. This study aimed to evaluate the proteomic response of Saccharomyces boulardii to simulated gastrointestinal digestion and the influence of encapsulation on yeast viability. Different pH values and time periods simulating the passage through different sections of the gastrointestinal tract were applied to unencapsulated and encapsulated yeasts. Encapsulation in 0.5% calcium alginate did not improve yeast survival or induce changes in protein patterns whereas protein extracts from control and digested yeasts showed remarkable differences when separated by SDS-PAGE. Protein bands were analyzed by tandem mass spectrometry. Protein identification revealed unique proteins that changed acutely in abundance after simulated digestion. Carbohydrate metabolism, protein processing, and oxide-reduction were the biological processes most affected by simulated gastrointestinal digestion in S. boulardii.

Biotechnological potential of bacteria isolated from cattle environments of desert soils in Sonora Mexico.

The aim of this research was to study the hydrolytic potential of bacteria isolated from cattle environments of two desert soils in one of the driest and hottest zones in America. A total of 26 points were sampled, 144 strains were isolated, and 50 strains were selected for the characterization of esterase, lipase, protease, and amylase activities and for 16S rRNA identification. Strains of the Bacillus, Pseudomonas, Acinetobacter, Enterobacter, Providencia, Escherichia, and Pantoea genera were identified. Comparisons of the proteolytic activity of the secretome from 14 strains (Bacillus n = 7, Escherichia n = 2; Providencia, Pseudomonas, Enterobacter, Pantoea and Acinetobacter n = 1) were performed. Four strains of Bacillus showed the highest proteolytic activity. These strains were characterized through a comparative analysis of pH and temperature as well as the effects of salt concentration on protease activity. Maximum proteolytic activity occurred in the range of pH 7-9 and temperatures between 50 and 70 °C for B. subtilis WD01, B. tequilensis WS11, B. tequilensis WS13, and B. tequilensis WS14. At a 20% NaCl concentration, the proteolytic activity retained was 71.4%, 65%, and 79.8% for WD01, WS11, and WS13, respectively; the activity of strain WS14 increased with 45% NaCl. Protease production by B. tequilensis WS14 with wheat, fish, and bone flours as low-cost substrates showed no differences between bone and fish flours and showed a decrease in protease production with wheat flour. The proteolytic activity in flour extracts with 20% NaCl was 82%, 75.61% and 38.04% for fish, bone and wheat flours, respectively. Data obtained in this work allow us to propose that strains isolated from environments with extreme conditions have a biotechnological potential.

Rhizospheric Microbiome Profiling of Capsicum annuum L. Cultivated in Amended Soils by 16S and Internal Transcribed Spacer 2 rRNA Amplicon Metagenome Sequencing.

Rhizospheric microbiomes of Capsicum annuum L. cultivated either conventionally or amended with a synthetic microbial consortium or a root exudate inductor, were characterized by 16S/internal transcribed spacer 2 (ITS2) rRNA amplicon metagenome sequencing. The most abundant taxa found, although differently represented in each treatment, were Gammaproteobacteria, Alphaproteobacteria, Actinobacteria, and Bacilli, as well as Chytridiomycetes and Mortierellomycotina.

Physicochemical and antioxidant characterization of Justicia spicigera.

Extracts with water:ethanol (100:0, 70:30, 50:50, 30:70, 0:100) solutions from fresh (F), just dried (JD), dried and stored for one year (DS) Justicia spicigera leaves were obtained using the stirring and ultrasound techniques. Extracts were analyzed in physicochemical and antioxidant characteristics. Identification of chemical compounds by gas chromatography-mass spectroscopy (GC-MS) was also performed. 2.14±0.91, 5.67±1.70, and 8.52±4.97g Gallic acid equivalents/100g dry weight (d.w.) of phenolic compounds were found, in average, for F, JD, and DS J. spicigera, respectively. 2.22±1.31, 2.58±2.11, and 8.48±3.78g Trolox equivalents/100g d.w. were detected with the ABTS method and 0.49±0.33, 1.23±0.87, and 0.88±0.94g with the DPPH method for F, JD and DS J. spicigera, respectively. Eucalyptol, phytol, and azulene were identified as the main compounds. J. spicigera showed colors (green-iridescent, green-yellow, or pink of different intensities) and antioxidant characteristics depending on the solvent concentration. Extracts could be used in the food and pharmaceutical industries.

Biotransformation and improved enzymatic extraction of chlorogenic acid from coffee pulp by filamentous fungi.

The highest enzymatic extraction of covalent linked chlorogenic (36.1%) and caffeic (CA) (33%) acids from coffee pulp (CP) was achieved by solid-state fermentation with a mixture of three enzymatic extracts produced by Aspergillus tamarii, Rhizomucor pusillus, and Trametes sp. Enzyme extracts were produced in a practical inexpensive way. Synergistic effects on the extraction yield were observed when more than one enzyme extract was used. In addition, biotransformation of chlorogenic acid (ChA) by Aspergillus niger C23308 was studied. Equimolar transformation of ChA into CA and quinic acids (QA) was observed during the first 36 h in submerged culture. Subsequently, after 36 h, equimolar transformation of CA into protocatechuic acid was observed; this pathway is being reported for the first time for A. niger. QA was used as a carbon source by A. niger C23308. This study presents the potential of using CP to produce enzymes and compounds such as ChA with biological activities.

Biotransformation of ferulic acid to 4-vinylguaiacol by a wild and a diploid strain of Aspergillus niger.

Ferulic acid biotransformation has a number of interesting industrial uses. Ferulic acid biotransformation by the wild strain Aspergillus niger C28B25 and a diploid strain DAR2, obtained by parasexual recombination, was studied. The wild strain of A.niger C28B25 biotransforms ferulic acid to vanillic acid (VA); while the diploid strain DAR2 preferentially decarboxylates ferulic acid to 4-vinylguaiacol (4VG). The latter was identified by mass spectroscopy, (1)H and (13)C nuclear magnetic resonance spectroscopy, and quantified by HPLC. The diploid strain A.niger DAR2 and the wild strain showed a ferulic acid conversion of 64% and 36%, respectively. Molar yields show that the formation of 4VG was preferred, being as much as 4.4 times higher than the formation of VA in diploid strain cultures. Differential regulation of enzymes involved in the biotransformation of ferulic acid may explain the accumulation of 4VG by diploid DAR2. This strain produced both 4VG and VA.