OVAT Analysis and Response Surface Methodology Based on Nutrient Sources for Optimization of Pigment Production in the Marine-Derived Fungus Talaromyces albobiverticillius 30548 Submerged Fermentation

Back to nature, microbial production of pigments and colorants for food use

Pigments-producing microorganisms are quite common in Nature. However, there is a long journey from the Petri dish to the market place. Twenty-five years ago, scientists wondered if such productions would remain a scientific oddity or become an industrial reality. The answer is not straightforward as processes using fungi, bacteria or yeasts can now indeed provide carotenoids or phycocyanin at an industrial level. Another production factor to consider is peculiar as Monascus red colored food is consumed by more than one billion Asian people; however, still banned in many other countries. European and American consumers will follow as soon as "100%-guaranteed" toxin-free strains (molecular engineered strains, citrinin gene deleted strains) will be developed and commercialized at a world level. For other pigmented biomolecules, some laboratories and companies invested and continue to invest a lot of money as any combination of new source and/or new pigment requires a lot of experimental work, process optimization, toxicological studies, and regulatory approval. Time will tell whether investments in pigments such as azaphilones or anthraquinones were justified. Future trends involve combinatorial engineering, gene knock-out, and the production of niche pigments not found in plants such as C50 carotenoids or aryl carotenoids.

Plant-microbe hybrid synthesis provides new insights for the efficient use of Macleaya cordata

Sanguinarine and chelerytrine have antibacterial and anti-inflammatory effects and is the main active ingredients of growth promoters in animals. Currently, Sanguinarine and chelerytrine were extracted from the capsules of the medicinal plant Macleaya cordata. However, the biomass of M. cordata nonmedicinal parts (leaves) accounted for a large proportion and contained a rich presentation of protopine and allocryptopine which are the precursor compounds of sanguinarine and chelerytrine. The aim of this study was to develop a new method for producing sanguinarine and chelerytrine through yeast transformation of protopine and allocryptopine in M. cordata leaves. First, we isolated different genes from Papaver somniferum (PsP6H, PsCPR, PsDBOX), Eschscholtzia californica (EcP6H), Cucumis sativus (CuCPR), Arabidopsis thaliana (AtCPR) and M. cordata (Mc11229, Mc11218, Mc6408, Mc6407, Mc19967, Mc13802). Additionally, some of the gene sequences were codon optimized. Then, we transformed these genes into yeast cells to compare the catalytic efficiency. Second, we used the most efficient strains to biotransform the leaves of M. cordata. Finally, we obtained 85.415 ± 11.887 ng mL^-1 sanguinarine and 4.288 ± 1.395 ng mL^-1 chelerytrine, which was more than 2-3 times the content in leaves of M. cordata. Overall, we using the nonmedicinal parts of M. cordata and successfully obtained sanguinarine and chelerytrine by the plant-microbial hybrid synthesis method.

Simultaneous Determination of Sulfonamides Antibiotics in Environmental Water and Seafood Samples Using Ultrasonic-Assisted Dispersive Liquid-Liquid Microextraction Coupled with High Performance Liquid Chromatography

The residues and abuse of antibiotics have seriously endangered ecological balance and human health; meanwhile, antibiotics determination is very difficult because of their low levels and multiple categories in complicated matrices. Appropriate sample pretreatment is usually imperative to enrich (ultra)trace antibiotics and eliminate matrix interference prior to chromatographic analysis. Dispersive liquid-liquid microextraction (DLLME) has become an ideal pretreatment technique owing to its simplicity, effectiveness, low-consumption, etc. In this work, an ultrasonic-assisted DLLME (UA-DLLME) was developed for the simultaneous extraction of seven sulfonamides (SAs) antibiotics in environmental water and seafood samples coupled with HPLC-DAD determination. Several parameters affecting UA-DLLME efficiency were systematically optimized, and consequently the SAs were separated and detected within 14.5 min. The obtained limits of detection (LODs) and limits of quantification (LOQs) ranged from 0.7-7.8 μg/L and 2.4-26.0 μg/L for three water samples (seawater, aquaculture wastewater and lake water) and two seafood samples (pomfrets and shrimps). High recoveries (80.0-116.0%) with low relative standard deviations (0.1-8.1%) were achieved for all the tested samples at three spiked levels. Notably, sulfadimethoxine was found at 24.49 μg/L in one seawater sample. The facile, robust and benign DLLME-HPLC method demonstrated promising perspectives for multiresidue analysis of antibiotics.

Cloning, expression and characterization of laccase from Bacillus licheniformis NS2324 in E. coli application in dye decolorization

Laccase gene from Bacillus licheniformis NS2324 was cloned and expressed in E. coli by using pUC 18 as cloning vector and pet 15b as expression vector. The purified recombinant laccase (rLacNS2324) showed a molecular mass of 66 KDa. The optimum pH and temperature for rLacNS2324 was found to be pH 8 and 40 °C respectively. The half life of rLacNS2324 at pH 7, 8 and 9 is 24 h. The half life of laccase at 45 °C is 8 h. Laccase activity was increased in the presence of Cu²⁺ (135.3%), Mn²⁺ (283.76%), and Co²⁺ (199.96%) at 5 mM of concentration, but inhibited to 17.01% in the presence of 5 mM Zn²⁺ ions. rLacNS2324 was found tolerant to NaCl and NaI. Among the inhibitors, it was found to be tolerant to EDTA, however, its activity was inhibited in the presence of sodium azide, dithiothreitol and β-mercapethanol. rLacNS2324 was able to decolorize a bromophenol blue by 85% and phenol red by 75% in 1 h without any mediator. Methylene blue was almost completely degraded (99.28% decolorization) by 10 IUml^-1 of laccase at 40 °C, pH 8.0 and in time 4 h. Overall rLacNS2324 showed ability to be used industrially to decolorize dyes in an eco-friendly and cost effective way.