Assessing three industrially produced fungi for the bioremediation of diclofenac.

Diclofenac is an emerging pollutant: toxic, persistent, and bioaccumulative, present in several environmental niches in a concentration of parts per million. This pharmaceutical's biological removal was reported with various fungal species, showing promissory results. This work aimed at diclofenac removal by individually challenging the fungal species Pleurotus ostreatus, Aspergillus niger, and Penicillium roquefortii but triying to lower the biosorption nature of cell walls by NaCl addition. P. ostreatus removed 100% of the initial diclofenac concentration, whereas A. niger and P. roqueforti removed 74% and 32%, respectively. In all three cases, biosorption by polar interactions was negligible. We demonstrated that stressful environments, such as mineral media, force the fungus to take advantage of its metabolic tools to survive, hence showing higher removal capacity when limiting growth conditions. Bioremediation is an excellent alternative to give residual fungal biomass a secondary use.

Effect of green and red light in lipid accumulation and transcriptional profile of genes implicated in lipid biosynthesis in Chlamydomonas reinhardtii.

Microalgae have the potential to accumulate triacylglycerols under different light spectra. In this work, Chlamydomonas reinhardtii was grown under white (400-700 nm), red (650 nm), and green (550 nm) lights. According to our results, red light (650 nm) has a positive effect in the microalgae growth and chlorophyll concentration. About the lipid content, the control culture (white light-illuminated) reached a 4.4% of dry cell weight (dcw), whereas the culture grown at 550 nm showed an increase of 1.35-fold in the lipids accumulation (5.96% dcw). Interestingly, the most significant accumulation was found in the culture grown at 650 nm (14.78% dcw) which means 3.36-fold higher with respect to the white light-illuminated culture. The most abundant fatty acids found in lipid extracts obtained from the cultures under different light wavelength were palmitic (C16: 0), oleic (C18: 1n9), stearidonic (C18: 4), and linoleic (C18: 2), which are useful in the biodiesel production. Changes in gene expression in response to different wavelength illuminations were assessed; however, an in-depth analysis of a larger number of genes involved in lipid biosynthesis is necessary to fully explain the highest accumulation of lipids in the culture grown under red light. This approach will be useful to find a sustainable source of lipids for biodiesel production. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1404-1411, 2016.

Proteomic analysis of Trichoderma atroviride reveals independent roles for transcription factors BLR-1 and BLR-2 in light and darkness.

The genus Trichoderma is one of the most widely used biological control agents of plant-pathogenic fungi. The main mechanism for survival and dispersal of Trichoderma is through the production of asexual spores (conidia). The transition from filamentous growth to conidiation can be triggered by light, nutrient deprivation, and mechanical damage of the mycelium. We conducted proteomic profiling analyses of Trichoderma atroviride after a blue light pulse. The use of two-dimensional electrophoresis (2-DE) and mass spectrometry (MS) analysis allowed us to identify 72 proteins whose expression was affected by blue light. Functional category analysis showed that the various proteins are involved in metabolism, cell rescue, and protein synthesis. We determined the relationship between mRNA levels of selected genes 30 min after a light pulse and protein expression levels at different times after the pulse and found this correlation to be very weak. The correlation was highest when protein and mRNA levels were compared for the same time point. The transcription factors BLR-1 and BLR-2 are vital to the photoconidiation process; here we demonstrate that both BLR proteins are active in darkness and affect several elements at both the transcript and protein levels. Unexpectedly, in darkness, downregulation of proteins prevailed in the Δblr-1 mutant, while upregulation of proteins predominated in the Δblr-2 mutant. Our data demonstrate that the BLR proteins play roles individually and as a complex.