Mucor Indicus Research Articles

Effect of phosphate concentration on exergetic-based sustainability parameters of glucose fermentation by Ethanolic Mucor indicus

In this work, a holistic exergetic-based framework was developed to assess the sustainability and productivity of a batch bioreactor used for ethanol production by ethanolic fungus Mucor indicus. Analyses were carried out in order to identify the most exergetically-sustainable concentration of phosphorous compound to produce ethanol and biomass. The microorganisms were aerobically cultivated using glucose as carbon source at various phosphate concentrations ranging from 0.0 to 7.5 g/L. The results obtained showed that the exergetic parameters of the fermentation process were remarkably influenced by the concentration of phosphate. Generally, the findings achieved revealed 3.5 g/L phosphate concentration as the most optimal fermentation condition from the exergetic point of view. Under this condition, the process exergetic efficiency and normalized exergy destruction as decision making parameters were found to be 53.42% and 0.48 kJ/kJ product, respectively. Moreover, the rational and process sustainability indexes for this concentration were determined at 3.92 and 2.15, respectively. The developed framework could be easily transplanted to evaluate the renewability of various lab-scale biofuel production processes to meet the goals laid forth for sustainable development.

New insight into microbial diversity and functions in traditional Vietnamese alcoholic fermentation

The roles of microorganisms in traditional alcoholic fermentation are often assumed based on abundance in the starter and activity in pure culture. There is a serious lack of hard evidence on the behavior and activity of individual microbial species during the actual fermentation process. In this study, microbial succession and metabolite changes during 7days of traditional Vietnamese alcoholic fermentation were monitored. Special attention was devoted to starch degradation. In total, 22 microbial species, including 6 species of filamentous fungi (Rhizopus microsporus, Rhizopus arrhizus, Mucor indicus, Mucor circinelloides, Cunninghamella elegans, Aspergillus niger), 1 yeast-like fungus (Saccharomycopsis fibuligera), 7 yeasts (Saccharomyces cerevisiae, Clavispora lusitaniae, Wickerhamomyces anomalus, Lindnera fabianii, Pichia kudriavzevii, Candida rugosa, Candida tropicalis), and 8 bacteria (Stenotrophomonas maltophilia, Lactobacillus brevis, Lactobacillus helveticus, Acinetobacter baumannii, Staphylococcus hominis, Bacillus megaterium, Enterobacter asburiae, Pediococcus pentosaceus) were identified. Despite the presence of a complex microbiota in the starter, the fermentation process is consistent and involves a limited number of functional species. Rapid change in microbial composition of fermentation mash was observed and it was correlated with ethanol content. Microbial biomass reached maximum during first 2days of solid state fermentation. Acidification of the medium took place in day 1, starch degradation in days 2, 3, 4, and alcohol accumulation from day 3. Although Sm. fibuligera dominated by cell count amongst potential starch degraders, zymography indicated that it did not produce amylase in the fermentation mash. In mixed culture with Rhizopus, amylase production by Sm. fibuligera is regulated by the moisture content of the substrate. Rhizopus was identified as the main starch degrader and S. cerevisiae as the main ethanol producer. Bacterial load was high but unstable in species composition and dominated by acid producers. M. indicus, Sm. fibuligera, W. anomalus and bacteria were regarded as satellite microorganisms. Their possible influence on organoleptic quality of fermentation product was discussed.

Ethanol production from alkali-pretreated oil palm empty fruit bunch by simultaneous saccharification and fermentation with mucor indicus

ABSTRACTOil palm empty fruit bunch (OPEFB) is a potential raw material for production of lignocellulosic bioethanol. The OPEFB was pretreated with 8% sodium hydroxide (NaOH) solution at 100°C for 10 to 90 min. Enzymatic digestion was carried out using cellulase and β-glucosidase at 45°C for 24 h. It was then inoculated with Mucor indicus spores suspension and fermented under anaerobic conditions at 37°C for 96 h. Sodium hydroxide pretreatment effectively removed 51–57% of lignin in the OPEFB and also its hemicellulose (40–84%). The highest glucan digestibility (0.75 g/g theoretical glucose) was achieved in 40-min NaOH pretreatment. Fermentation by M. indicus resulted in 68.4% of the theoretical ethanol yield, while glycerol (16.2–83.2 mg/g), succinic acid (0–0.4 mg/g), and acetic acid (0–0.9 mg/g) were its by-products. According to these results, 11.75 million tons of dry OPEFB in Indonesia can be converted into 1.5 billion liters of ethanol per year.

Hyphal tip cytoplasmic organization in four zygomycetous fungi

We have examined the hyphal tip structure in four zygomycetous fungi: Mortierella verticillata (Mortierellales), Coemansia reversa (Kickxellales), Mucor indicus and Gilbertella persicaria (Mucorales) using both light and transmission electron microscopy. We have used cryofixation and freeze-substitution methods to preserve fungal hyphae for transmission electron microscopy, which yielded improved preservation of ultrastructural details. Our research has confirmed studies that described the accumulation of secretory vesicles as a crescent at the hyphal apex (i.e. the apical vesicle crescent [AVC]) and provided a more detailed understanding of the vesicle populations. In addition, we have been able to observe the behavior of the AVC during hyphal growth in M. indicus and G. persicaria.

Evaluation of Mucor indicus and Saccharomyces cerevisiae capability to ferment hydrolysates of rape straw and Miscanthus giganteus as affected by the pretreatment method

Rape straw and Miscanthus giganteus was pretreated chemically with oxalic acid or sodium hydroxide. The pretreated substrates were hydrolyzed with enzymatic preparations of cellulase, xylanase and cellobiase. The highest concentration of reducing sugars was achieved after hydrolysis of M. giganteus pretreated with NaOH (51.53gdm−3). In turn, the highest yield of enzymatic hydrolysis determined based on polysaccharides content in the pretreated substrates was obtained in the experiments with M. giganteus and oxalic acid (99.3%). Rape straw and M. giganteus hydrolysates were fermented using yeast Saccharomyces cerevisiae 7, NRRL 978 or filamentous fungus Mucor rouxii (Mucor indicus) DSM 1191. The highest ethanol concentration was determined after fermentation of M. giganteus hydrolysate pretreated with NaOH using S. cerevisiae (1.92% v/v). Considering cellulose content in the pretreated solid, the highest degree of its conversion to ethanol (86.2%) was achieved after fermentation of the hydrolysate of acid-treated M. giganteus using S. cerevisiae.

Nickel Biosorption by Fungal Chitosan from <I>Mucor Indicus</I>

Nickel Biosorption by Fungal Chitosan from <I>Mucor Indicus</I>

Co-Production of Fungal Biomass Derived Constituents and Ethanol from Citrus Wastes Free Sugars without Auxiliary Nutrients in Airlift Bioreactor

The potential of two zygomycetes fungi, Mucor indicus and Rhizopus oryzae, in assimilating citrus waste free sugars (CWFS) and producing fungal chitosan, oil, and protein as well as ethanol was investigated. Extraction of free sugars from citrus waste can reduce its environmental impact by decreasing the possibility of wild microorganisms growth and formation of bad odors, a typical problem facing the citrus industries. A total sugar concentration of 25.1 g/L was obtained by water extraction of citrus waste at room temperature, used for fungal cultivation in shake flasks and airlift bioreactor with no additional nutrients. In shake flasks cultivations, the fungi were only able to assimilate glucose, while fructose remained almost intact. In contrast, the cultivation of M. indicus and R. oryzae in the four-liter airlift bioreactor resulted in the consumption of almost all sugars and production of 250 and 280 g fungal biomass per kg of consumed sugar, respectively. These biomasses correspondingly contained 40% and 51% protein and 9.8% and 4.4% oil. Furthermore, the fungal cell walls, obtained after removing the alkali soluble fraction of the fungi, contained 0.61 and 0.69 g chitin and chitosan per g of cell wall for M. indicus and R. oryzae, respectively. Moreover, the maximum ethanol yield of 36% and 18% was obtained from M. indicus and R. oryzae, respectively. Furthermore, that M. indicus grew as clump mycelia in the airlift bioreactor, while R. oryzae formed spherical suspended pellets, is a promising feature towards industrialization of the process.

Exergy-based sustainability assessment of ethanol production via Mucor indicus from fructose, glucose, sucrose, and molasses

This paper presents an in-depth exergy analysis of the ethanol fermentation process with various forms of fungus Mucor indicus under aerobic and anaerobic conditions to select the most productive and sustainable conditions. Various carbon sources including fructose, glucose, and sucrose as well as the whole and inverted sugar beet and sugarcanes molasses were used during the fermentation. The rational and process exergetic efficiencies were found to be in the range of 65.21%–88.54% and 0.00%–44.31%, respectively. Overall, the exergy-based parameter based on the process outputs could provide useful information about the sustainability and productivity of the fermentation process compared to the rational analysis. More specifically, the inverted sugar beet molasses with MF (mostly filamentous) form of M. indicus under anaerobic cultivation was shown to be the best option for industrial production phase with respect to the productivity and sustainability issues. The results obtained confirmed that the process yield alone cannot perfectly reflect the exact sustainability parameters of the renewable ethanol production systems. Finally, the developed exergetic framework could help engineers to couple biochemical and physical concepts more robustly for achieving the most cost-effective and eco-friendly pathways for bioethanol production.

Mucor indicus isolated from the semiarid region of Brazil: a first record for South America

A specimen of Mucor indicus was isolated from a dung sample collected in the city of Sertânia in the Brazilian state of Pernambuco and its identity confirmed through LSU rDNA sequence analysis. The taxon is described and illustrated for the first time from South America. An identification key is provided for Mucor species from the northeast Brazilian semiarid region (Caatinga).

Effect of Acid and Alkaline Pretreatment on the Production of Biosurfactant from Rice Husk Using Mucor indicus

Effect of Acid and Alkaline Pretreatment on the Production of Biosurfactant from Rice Husk Using Mucor indicus

FTIR Analysis and Optimization of Simultaneous Saccharification and Fermentation Parameters for Sustainable Production of Ethanol from Peels of Ananas cosmosus by Mucor indicus MTCC 4349

The pulverized A. cosmosus peel was found to contain 25 ± 0.31 % cellulose, 28 ± 0.18 % hemicellulose and 8 ± 0.07 % of lignin on dry solid basis. 1 % H2SO4 delignified A. cosmosus peel yielded 38.81 % xylose, 29.31 % fructose and 18.89 % glucose under steam explosion, with a hydrolytic efficiency of 75.52 %. Fourier transform infrared spectroscopy results not only indicated the penetration of H2SO4 in the amorphous region of the biomass and degradation of hemicelluloses but also shows the structural differences before and after pretreatment. Simultaneous Saccharification and Fermentation of pretreated A. cosmosus peel by cellulase and Mucor indicus MTCC 4349 were investigated in the present study. Important process variables for ethanol production from pretreated A. cosmosus peel were optimized using Response Surface Methodology (RSM) based on central composite design (CCD) experiments. A three level CCD experiments with central and axial points was used to develop a statistical model for the optimization of process variables such as incubation temperature (30, 32 and 34 °C) X1, inoculum level (2, 4 and 6 %) X2 and nutrients (1/2/3) X3. Data obtained from RSM on ethanol production were subjected to the analysis of variance and analyzed using a second order polynomial equation and contour plots were used to study the interactions among three relevant variables of the fermentation process. The fermentation experiments were carried out at flask level. The processing parameters setup for reaching a maximum response for ethanol production was obtained when applying the optimum values for temperature (30 °C), inoculum level (2 %) and fermentation medium (urea, NaH2PO4, tryptone and meat extract) for Mucor indicus MTCC 4349. Maximum ethanol concentration 10.4293 g/l was obtained after 72 h from Mucor indicus MTCC 4349 at the optimized process conditions in aerobic batch fermentation.

Fungal Infections After Boston Type 1 Keratoprosthesis Implantation: Literature Review and In Vitro Antifungal Activity of Hypochlorous Acid.

To review the current literature describing cases of fungal keratitis and endophthalmitis after Boston keratoprosthesis (KPro) implantation and to characterize the antifungal activity of 0.01% hypochlorous acid against medically relevant fungi. A literature review of fungal keratitis or endophthalmitis in KPro patients from January 2001 to April 2015, and an in vitro time kill assay characterizing the fungicidal activity of 0.01% hypochlorous acid against fungi causing ocular infections. Fifteen publications, predominantly retrospective case series, were identified. Infection rates after KPro implantation ranged from 0.009 to 0.02 fungal infections per patient-year of follow-up. The largest single-surgeon series reported an incidence of 2.4% for fungal endophthalmitis during a 10-year period. Causative organisms included both yeasts and molds. Outcomes were favorable if infections were caught early and treated appropriately; less favorable outcomes were reported in developing countries where fungal species are endemic and resources are limited. 0.01% hypochlorous acid is rapidly fungicidal, reducing the number of viable yeast cells or mold conidia by at least 99.99% within 60 seconds. The antifungal activity extended to all molds (Acremonium kiliense, Aspergillus flavus, Aspergillus fumigatus, Fusarium solani, and Mucor indicus) and yeast species (Candida albicans and Candida parapsilosis) tested. Fungal infections remain a lifelong concern in patients after KPro implantation. There is a growing need for a standard antifungal prophylaxis regimen, especially in the developing world. The rapid broad-spectrum in vitro fungicidal activity of 0.01% hypochlorous acid against all fungi tested makes it an attractive candidate as an antifungal prophylaxis in KPro patients.

Kinetics Studies of the Partially Purified Cellulase Produced During the Degradation of Rice Husk Pre-Treated at Different pHs Using Mucor indicus

Kinetics Studies of the Partially Purified Cellulase Produced During the Degradation of Rice Husk Pre-Treated at Different pHs Using Mucor indicus

Oil, chitosan, and ethanol production by dimorphic fungus Mucor indicus from different lignocelluloses

AbstractBACKGROUNDMucor indicus is a dimorphic fungus capable of producing ethanol, with numerous advantages compared with Saccharomyces cerevisiae.RESULTSCellulose solvent‐ and organic solvent‐based lignocellulosic fractionation (COSLIF) enhanced the enzymatic hydrolysis yield and especially the initial hydrolysis rate. Effects of the fungal morphology on the major metabolites, i.e., ethanol and biomass ingredients (fatty acids and chitosan) were investigated. Purely yeast‐like form yielded 78–92% of the maximum theoretical ethanol yield with 0.43–0.64 g L−1 h−1 productivity, whereas fermentation by purely filamentous form resulted in the yield and productivity of 48–66% and 0.3–0.4 g L−1 h−1, respectively. Beside ethanol, the fungus produced a large amount of chitin‐chitosan (62–67% of the fungal alkali insoluble materials) in filamentous form, while the value was 41–45% for yeast‐like form. Furthermore, yeast‐like cells produced nutritionally valuable fatty acids at a rate higher than that by filamentous form (3.7 and 2.7%, respectively). Linoleic acid, a polyunsaturated omega‐6, was the dominant fatty acid available in the biomass with both morphologies.CONCLUSIONSThe fermentation products were significantly dependent on the fungus morphology but not on the lignocellulose type. Yeast‐like cells exhibited better performance in ethanol and oil production, whereas the filamentous cells produced higher amounts of chitosan. © 2015 Society of Chemical Industry

Effects of Plant Growth Hormones on Mucor indicus Growth and Chitosan and Ethanol Production.

The objective of this study was to investigate the effects of indole-3-acetic acid (IAA) and kinetin (KIN) on Mucor indicus growth, cell wall composition, and ethanol production. A semi-synthetic medium, supplemented with 0–5 mg/L hormones, was used for the cultivations (at 32 °C for 48 h). By addition of 1 mg/L of each hormone, the biomass and ethanol yields were increased and decreased, respectively. At higher levels, however, an inverse trend was observed. The glucosamine fraction of the cell wall, as a representative for chitosan, followed similar but sharper changes, compared to the biomass. The highest level was 221% higher than that obtained without hormones. The sum of glucosamine and N-acetyl glucosamine (chitin and chitosan) was noticeably enhanced in the presence of the hormones. Increase of chitosan was accompanied by a decrease in the phosphate content, with the lowest phosphate (0.01 g/g cell wall) being obtained when the chitosan was at the maximum (0.45 g/g cell wall). In conclusion, IAA and KIN significantly enhanced the M. indicus growth and chitosan production, while at the same time decreasing the ethanol yield to some extent. This study shows that plant growth hormones have a high potential for the improvement of fungal chitosan production by M. indicus.

Microbial community structure and dynamics during the traditional brewing of Fuzhou Hong Qu glutinous rice wine as determined by culture-dependent and culture-independent techniques

The aim of this study was to investigate the bacterial and fungal community structure and dynamics during the traditional brewing of Fuzhou Hong Qu glutinous rice wine through culture-dependent and culture-independent methods. The culture-independent DGGE profiles revealed the presence of eleven bacterial species (Janthinobacterium lividum, Lactobacillus plantarum, Weissella soli, Leuconostoc mesenteroides, Lactobacillus brevis, Pediococcus pentosaceus, Lactococcus lactis subsp. lactis, Pediococcus acidilactici, Bacillus subtilis, Bacillus aryabhattai and Bacillus megaterium) and seven fungal species (Saccharomycopsis fibuligera, Pichia guilliermondii, Saccharomyces cerevisiae, Wickerhamomyces anomalus, Rhizopus oryzae, Candida glabrata and Monascus purpureus) during the traditional brewing process. Furthermore, the microbial compositions of fermented samples were investigated using culture-dependent approach (conventional plate count technique combined with molecular identification). Results showed that the relative proportions of some fungal species (C. glabrata, W. anomalus, P. guilliermondii and S. fibuligera) and bacterial species (Lc. lactis subsp. lactis, Staphylococcus pasteuri, Bacillus sp., P. pentosaceus) detected at the early brewing stage decreased as the fermentation progressed, while S. cerevisiae, L. brevis, L. plantarum and Lactobacillus paracasei became the predominant species during the late brewing period. Some differences were also found between the profiles obtained by PCR–DGGE and culture-dependent technique. Comparative analysis revealed that some species (J. lividum, W. soli, B. aryabhattai and P. guilliermondii) could only be detected using PCR–DGGE technique. Conversely, some species (L. paracasei, S. pasteuri, Bacillus methylotrophicus, Mucor indicus and Aspergillus flavus) could only be detected by culture-dependent method. Therefore, the combination of culture-dependent and -independent approaches is quite necessary because they provided complementary information about the composition of the microbial community during the traditional brewing of Fuzhou Hong Qu glutinous rice wine. This study provides the first detailed evaluation of fungal community and dynamics in Fuzhou Hong Qu glutinous rice wine traditional brewing process using culture-dependent and -independent methods, which would facilitate scientific understanding of the traditional brewing mechanism and be useful for the selection of the suitable and beneficial strains to improve the wine quality.

Downstream optimization of fungal-based simultaneous saccharification and fermentation relevant to lignocellulosic ethanol production.

To support the inefficient limitation of long-term biosystem by well-known simultaneous saccharification and fermentation (SSF), electron beam irradiated rice straw (at 80 kGy, 1 MeV, and 0.12 mA) was fermented using fungal-based simultaneous saccharification and fermentation (FBSSF) by saprophytic zygomycetes Mucor indicus. Based on the growth optimization (by response surface methodology), this eco-friendly bioprocess either without metabolic inhibitors (especially furfurals and acetic acids) or byproducts (especially glycerols) significantly increased the biodegradability and fermentability of lignocellulosic rice straw. Specifically, when irradiated straw was simultaneously bioconverted by M. indicus for 48 h, the ethanol yield was 57.2% of the theoretical maximum. This value was on the similar level as the 59.8% (for 144 h) measured from processed straw by well-known SSF. Furthermore, after FBSSF for 144 h based on large-scale mass balance, the ethanol concentration and production yield, and productivity were 34.6 g/L, 72.3% of the theoretical maximum, and 0.24 g/L/h, respectively.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-015-0825-x) contains supplementary material, which is available to authorized users.

Successful Treatment of a Necrotizing Fasciitis Patient Caused by Mucor indicus with Amphotericin B and Skin Grafting

Cutaneous mucormycosis, an uncommon disease caused by Mucorales, predominantly occurs in immunocompromised host. The present case is a primary cutaneous mucormycosis due to Mucor indicus in an immunocompetent individual. It is with the features of necrotizing fasciitis over the right pretibial area. We are presenting this case owing to its rarity and the successful treatment with amphotericin B and skin grafting.

Effect of Phosphate on Glucosamine Production by Ethanolic Fungus Mucor indicus

In this study, the effect of phosphorous compound concentration on the production of glucosamine by Mucor indicus was investigated. Changes in the yield of ethanol, the major metabolite of the fungus, were also followed besides. The alkali insoluble material of the biomass of the fungus mainly contained phosphates and polymers of glucosamine and N-acetyl glucosamine, i.e., chitin and chitosan. Yields of glucosamine (78-113g/kg dry fungal biomass) and ethanol (200-370g/kg glucose) were significantly affected by the phosphorous concentration. The results showed that lower concentrations of phosphorous favored the production of glucosamine while higher ethanol as well as biomass yields was obtained at higher concentrations. The best concentration was 0.5g/l where glucosamine yield was 0.37g/l (11% of the biomass). At this phosphate concentration, ethanol and biomass yields were 360 and 76g/kg glucose, respectively. On average, proteins comprised 51.5% of the biomass. Glycerol was the second important metabolite during the fermentation by the fungus which appeared at lower yields (20-34g/kg glucose).

Enhanced ethanol and chitosan production from wheat straw by Mucor indicus with minimal nutrient consumption

Recently, Mucor indicus was introduced as a promising ethanol producing microorganism for fermentation of lignocellulosic hydrolysates, showing a number of advantages over Saccharomyces cerevisiae. However, high nutrient requirement is the main drawback of the fungus in efficient ethanol production from lignocelluloses. In this study, application of fungal extract as a potential nutrient source replacing all required nutrients in fermentation of wheat straw by M. indicus was investigated. Wheat straw was pretreated with N-methylmorpholine-N-oxide (NMMO) at 120°C for 1–5h prior to enzymatic hydrolysis. Hydrolysis yield was improved at least by 6-fold for 3h pretreated straw compared with that of untreated one. A fungal extract was produced by autolysis of M. indicus biomass, an unavoidable byproduct of fermentation. Maximum free amino nitrogen (2.04g/L), phosphorus (1.50g/L), and total nitrogen (4.47g/L) as well as potassium, magnesium, and calcium in the fungal extract were obtained by autolysis of the biomass at 50°C and pH 5.0. The fungal extract as a nutrient-rich supplement substituted yeast extract and all other required minerals in fermentation and enhanced the ethanol yield up to 92.1% of the theoretical yield. Besides, appreciate amounts of chitosan were produced as another valuable product of the autolysis.