Effects of hurdle technology on Monascus ruber growth in green table olives: a response surface methodology approach

ABSTRACT An ascomycetes fungus was isolated from brine storage of green olives of the Arauco cultivar imported from Argentina and identified as Monascus ruber. The combined effects of different concentrations of sodium chloride (3.5-5.5%), sodium benzoate (0-0.1%), potassium sorbate (0-0.05%) and temperature (30-40 °C) were investigated on the growth of M. ruber in the brine of stored table olives using a response surface methodology. A full 24 factorial design with three central points was first used in order to screen for the important factors (significant and marginally significant factors) and then a Face-Centered Central Composite Design was applied. Both preservatives prevented fungal spoilage, but potassium sorbate was the most efficient to control the fungi growth. The combined use of these preservatives did not show a synergistic effect. The results showed that the use of these salts may not be sufficient to prevent fungal spoilage and the greatest fungal growth was recorded at 30 °C.

Production of angkak through co-culture of Monascus purpureus and Monascus ruber

Angkak (red mold rice, red yeast rice, Chinese red rice) is a traditional Chinese medicine produced by solid-state fermentation of cooked non-glutinous rice with Monascus species. The secondary metabolite of Monascus species, monacolin K /lovastatin, has been proven to lower blood lipid levels. In this study, a co-culture of Monascus purpureus MTCC 369 and Monascus ruber MTCC 1880 was used for angkak production. Four medium parameters screened by Plackett-Burman design were optimized by response surface methodology for highest lovastatin production in angkak during solid-state fermentation by the co-culture. Maximum lovastatin production of 2.84 mg g-1 was predicted in solid medium containing 20 g rice and 40 ml liquid nutrients medium (malt extract 9.68 g l-1, dextrose 38.90 g l-1, MnSO4.H2O 1.96 g l-1, and MgSO4.7H2O 0.730 g l-1) by point prediction tool of Design Expert 7.1 software (Statease Inc. USA).

Production of angkak through co-culture of Monascus purpureus and Monascus ruber

Angkak (red mold rice, red yeast rice, Chinese red rice) is a traditional Chinese medicine produced by solid-state fermentation of cooked non-glutinous rice with Monascus species. The secondary metabolite of Monascus species, monacolin K /lovastatin, has been proven to lower blood lipid levels. In this study, a co-culture of Monascus purpureus MTCC 369 and Monascus ruber MTCC 1880 was used for angkak production. Four medium parameters screened by Plackett-Burman design were optimized by response surface methodology for highest lovastatin production in angkak during solid-state fermentation by the co-culture. Maximum lovastatin production of 2.84 mg g-1 was predicted in solid medium containing 20 g rice and 40 ml liquid nutrients medium (malt extract 9.68 g l-1, dextrose 38.90 g l-1, MnSO4.H2O 1.96 g l-1, and MgSO4.7H2O 0.730 g l-1) by point prediction tool of Design Expert 7.1 software (Statease Inc. USA).

Establishment of Two-dimensional Electrophoresis System for Proteome of Monascus ruber / 中国生物工程杂志

Two-dimensional electrophoresis(2-DE) is an important technique in proteomics research.The 2-DE system for proteome of Monascus ruber was established by comparing and analyzing the infection caused by different kinds of mediums,lysis buffer and the condition of rehydration.By cultivating the Monascus ruber with YES for 6 days,extracting total protein by TCA-acetone,lysis buffer with 8 mol/L urea,2 mol/L thiourea,4 % CHAPS,1 % DTT and 2 % Bio-lyte,an ideal 2-DE map with higher resolution and better legibility was obtained,which laid a foundation for the further studies on proteome of Monascus ruber.

The Targeted-deletion Technology in the Monascus ruber Mediated via Agrobacterium tumefaciens / 微生物学通报

Monascus spp.,a kind of filamentous fungi,produce abundant of important metabolites which were widely used in the fields of food and medicine.Until now,there are few reports on the important functional genes of the Monascus spp.due to little genetic information.In this paper,the feasibility of gene deletion mediated via Agrobacterium tumefaciens on the basis of homologous recombination was analyzed by studying on the deletion of the RGS domain of putative G-protein signaling regulator gene mrfA in Monascus ruber.The length of homologous arms of deletion vector pC805S were 958 bp and 824 bp,respectively.There were 26 transformants in which homologous recombination occurred in 138 transformants and the recombination rate was 18.8%.The result showed it was feasible to identify the function of unknown gene in M.ruber with the targeted-deletion technology mediated via A.tumefaciens.

Screening Citrinin Mutants from the Transformants Library of Monascus ruber M-7 by Agrobacterium-mediated DNA transfer / 微生物学通报

200 citrinin mutants were screened with the inhibition zone method from the transformants library of Monascus ruber M-7 by Agrobacterium-mediate DNA transfer, which contains more than 5,000 transformants.Then 53 mutants, whose citrinin contents ranged from 0.04?g/g to 154.57?g/g in the red fermented rice (RFR), were achieved by high performance liquid chromatography (HPLC).Color values of RFR prepared by these mutants were also detected.The results showed that there was a positive correlation between the citrinin content and the color value among the mutants.These results provide materials and research bases for ferrther studying the relationship between the production of citrinin and pigment of Monascus ruber at molecular level.