Plant metabolite 5-pentadecyl resorcinol is produced by the Amazonian fungus Penicillium sclerotiorum LM 5679

Since the classic studies of Alexander Flemming, Penicillium strains have been known as a rich source of antimicrobial substances. Recent studies have identified novel metabolites produced by Penicillium sclerotiorum that have antibacterial, antifouling and pharmaceutical activities. Here, we report the isolation of a P. sclerotiorum (LM 5679) from Amazonian soil and carry out a culture-based study to determine whether it can produce any novel secondary metabolite(s) that are not thus-far reported for this genus. Using a submerged culture system, secondary metabolites were recovered by solvent extract followed by thin-layer chromatography, nuclear magnetic resonance, and mass spectroscopy. One novel secondary metabolite was isolated from P. sclerotiorum (LM 5679); the phenolic compound 5-pentadecyl resorcinol widely known as an antifungal, that is produced by diverse plant species. This metabolite was not reported previously in any Penicillium species and was only found once before in fungi (that time, in a Fusarium). Here, we discuss the known activities of 5-pentadecyl resorcinol in the context of its mode-of-action as a hydrophobic (chaotropicity-mediated) stressor.

The Heterotrimeric Transcription Factor CCAAT-Binding Complex and Ca 2+ -CrzA Signaling Reversely Regulate the Transition between Fungal Hyphal Growth and Asexual Reproduction

A precisely timed switch between vegetative hyphal growth and asexual development is a crucial process for the filamentous fungal long-term survival, dissemination, biomass production, and virulence. However, under the submerged culture condition, filamentous fungi would undergo constant vegetative growth whereas asexual conidiation rarely occurs.

Biological production of citric acid in submerged culture of Aspergillus niger using cassava pulp wastes

Utilization of cassava pulp wastes for citric acid production was investigated using Aspergillus niger in a submerged culture. A series of experiments were designed on various fermentation parameters to establish the optimal conditions for citric acid production from cassava pulp. This study revealed that production parameters such as cassava pulp concentration, initial pH, incubation temperature, agitation, and nitrogen source and fermentation period had effect on the amount of citric acid produced from cassava pulp. Citric acid concentration increased as the concentration of cassava pulp increases up to 20% with maximum citric acid concentration of 14.9 ± 0.413 g/l after 120 hours of fermentation. pH 5.5 was the optimum with maximum citric acid concentration of 16.8 ± 0.23 g/l after 120 hours of fermentation. Incubation temperature at 300 C was the optimum, with citric acid concentration of 19.15 ± 0.43 g/l. Increased in agitation speed from 100 to 225 rpm gave the maximum citric acid concentration of 25.2 ± 0.32 g/l after 120 hours of fermentation. Soybean meal supplementation was the best maximum citric acid concentration of 28.2 ± 0.51 g/l. Evaluating the effect of different concentration of soybean meal shows that 0.3 % supplementation was the optimum with maximum concentration of 31.2 ±0.35g/l from cassava pulp after 120 hours of fermentation. The result suggested that citric acid can be accumulated using cassava pulp by Aspergillus niger in submerged culture during fermentation. Cassava pulp if well harnessed can be used for large scale citric acid production.

Mr-AbaA Regulates Conidiation by Interacting with the Promoter Regions of Both Mr-veA and Mr-wetA in Metarhizium robertsii

Metarhizium robertsii is an emerging model entomopathogenic fungus for developing biopesticides; therefore, a comprehensive understanding of its conidiation is very important for its application. In this study, we revealed that the transcription factor Mr-AbaA is involved in the control of aerial conidiation and blastospore separation in submerged culture.

Cytotoxicity analysis of biomass combustion particles in human pulmonary alveolar epithelial cells on an air–liquid interface/dynamic culture platform

Background Exposure to indoor air pollution from solid fuel combustion is associated with lung diseases and cancer. This study investigated the cytotoxicity and molecular mechanisms of biomass combustion-derived particles in human pulmonary alveolar epithelial cells (HPAEpiC) using a platform that combines air–liquid interface (ALI) and dynamic culture (DC) systems. Methods HPAEpiC were cultured on the surface of polycarbonate (PC) membranes on the ALI–DC platform. The cells were sprayed with an aerosolized solution of biomass combustion soluble constituents (BCSCs) and simultaneously nourished with culture medium flowing beneath the permeable PC membranes. The ALI–DC method was compared with the traditional submerged culture approach. BCSC particle morphology and dosages deposited on the chip were determined for particle characterization. Flow cytometry, scanning electron microscopy, and transmission electron microscopy were used to investigate the apoptosis rate of HPAEpiC and changes in the cell ultrastructure induced by BCSCs. Additionally, the underlying apoptotic pathway was examined by determining the protein expression levels by western blotting. Results Scanning electron microscope images demonstrated that the sample processing and delivering approach of the ALI–DC platform were suitable for pollutant exposure. Compared with the submerged culture method, a significant decline in cell viability and increase in apoptosis rate was observed after BCSC exposure on the ALI–DC platform, indicating that the ALI–DC platform is a more sensitive system for investigating cytotoxicity of indoor air pollutants in lung cells. The morphology and ultrastructure of the cells were damaged after exposure to BCSCs, and the p53 pathway was activated. The Bcl-2/Bax ratio was reduced, upregulating caspase-9 and caspase-3 expression and subsequently inducing apoptosis of HPAEpiC. The addition of N-acetyl cysteine antioxidant significantly alleviated the cytotoxicity induced by BCSCs. Conclusion A novel ALI–DC platform was developed to study the cytotoxicity of air pollutants on lung cells. Using the platform, we demonstrated that BCSCs could damage the mitochondria, produce reactive oxygen species, and activate p53 in HPAEpiC, ultimately inducing apoptosis.

Production of Minor Ginsenosides C-K and C-Y from Naturally Occurring Major Ginsenosides Using Crude β-Glucosidase Preparation from Submerged Culture of Fomitella fraxinea

Minor ginsenosides, such as compounds (C)-K and C-Y, possess relatively better bioactivity than those of naturally occurring major ginsenosides. Therefore, this study focused on the biotransformation of major ginsenosides into minor ginsenosides using crude β-glucosidase preparation isolated from submerged liquid culture of Fomitella fraxinea (FFEP). FFEP was prepared by ammonium sulfate (30–80%) precipitation from submerged culture of F. fraxinea. FFEP was used to prepare minor ginsenosides from protopanaxadiol (PPD)-type ginsenoside (PPDG-F) or total ginsenoside fraction (TG-F). In addition, biotransformation of major ginsenosides into minor ginsenosides as affected by reaction time and pH were investigated by TLC and HPLC analyses, and the metabolites were also identified by UPLC/negative-ESI-Q-TOF-MS analysis. FFEP biotransformed ginsenosides Rb1 and Rc into C-K via the following pathways: Rd → F2 → C-K for Rb1 and both Rd → F2→ C-K and C-Mc1 → C-Mc → C-K for Rc, respectively, while C-Y is formed from Rb2 via C-O. FFEP can be applied to produce minor ginsenosides C-K and C-Y from PPDG-F or TG-F. To the best of our knowledge, this study is the first to report the production of C-K and C-Y from major ginsenosides by basidiomycete F. fraxinea.

Effects of pine (Pinus densiflora) sawdust on cordycepin yield from medicinal fungus Cordyceps militaris in submerged culture

Cordycepin (3′-deoxyadenosine) is a nucleoside analog that exhibits a broad spectrum of biological activity. The effects of different tree sawdust on cordycepin as bioactive substances for mycelium growth were investigated. Pine sawdust was essential for increasing cordycepin content. Furthermore, a 1% NaOH-pretreated pine sawdust produced the highest cordycepin yield. The cordycepin yield of mycelium in submerged culture was significantly increased when the particle size was 100-mesh and the weight was 20 g/L of 1% NaOH-pretreated pine sawdust, with an increase of up to 38% compared to the control (only sabouraud dextrose broth (SDB)). The results demonstrated the effects of different tree sawdust on the biosynthesis of cordycepin as bioactive substances and that replacing traditional medium (SDB medium) with 1% NaOH-pretreated pine sawdust can increase the yield of cordycepin. After optimization of cordycepin production from Cordyceps militaris cultivated in medium containing 1% NaOH-pretreated pine sawdust using RSM (response surface methodology) BBD (Box-Behnken design) in its canonical form, the optimum combination was: particle size, 113.7-mesh; input weight, 11.9 g/L; and incubation time, 67.8 h. The model predicted a maximum yield of 922.6 μg/mL for cordycepin.

Screening and characterization of cellulolytic molds from empty fruit bunches and soils in palm oil plantation area in Indonesia

Objective This research was aimed to isolate cellulolytic molds in empty fruit bunches of oil palm (EFBOP) and soils from palm oil plantation area and identify their enzyme activities to digest EFBOP. Results A total of seven molds were successfully isolated and screened for their enzyme activities from EFBOP and the soils. The enzymes from each isolate were produced in submerged culture using Mineral Mandels and 3% of alkali pretreated pollard in triplicates. The results indicated that all of the isolates were able to hydrolyze Carboxymethyl Cellulose (CMC), Whatmann No. 1 filter paper, and also EFBOP to sugars with reducing ends that reacted to 3,5-Dinitrosalicylic acid (DNS). The CMCase activity of isolate X showed the highest while the lowest was found for isolate MT8. Filter paperase (FPase) activity of isolate X performed the highest wile the lowest were found from isolate MT3 and MT6. The saccharification activity of isolate P showed the highest while MT6 performed the lowest activity