Rhizopus Research Articles

The use of Rhizopus sp. mutant for lactic acid production by solid state fermentation

A fungal strain, Rhizopus sp. C018, is a promising filamentous fungus that produces L-(+)-lactic acid. In this study the wild strain of C018 was used for lactic acid production by solid state fermentation on cassava peel incubated at 30oC. The results showed that the strain could produce 32.4 mg/g of lactic acid at day three. Then, the wild strain of C018 was subjected to mutation by UV radiation and the mutant named UV 333 expressed the highest lactic acid production as 57.6 mg/g analyzed by Reflectometer RQflex® 10 Merck Germany at day three. For further studies, mutation by chemicals will be tested to obtain the maximum amount of lactic acid production.

균주를 달리하여 제조한 귤피 속성장의 특성

This study was performed to provide information for improving the quality characteristics of tangerine peel Soksungjang. Tangerine peel Soksungjangs were prepared with 10% tangerine peel powder by addition of different koji such as Rhizopus oligosporus (RS, RTS) and Aspergillus oryzae (AS, ATS). As a result, the moisture content was not changed and crude protein content decreased during fermentation in all samples. The pH of RS (Soksungjang manufactured with Rhizopus oligosporus koji) and RTS (Soksungjang manufactured with Rhizopus oligosporus koji and 10% tangerine peel powder) was not changed, whereas pH of AS (Soksungjang manufactured with Aspergillus oryzae) and ATS (Soksungjang manufactured with Aspergillus oryzae koji and 10% tangerine peel powder) decreased rapidly after 10 days of fermentation. The acidity values of all the samples increased during fermentation. The major free sugars were glucose, fructose, and maltose; while, the major organic acids were citric acid, succinic acid, acetic acid, and lactic acid in all the samples. The amino nitrogen content and protease activity were highest in the AS and ATS. Conversely, the reducing sugar content and α-amylase activity were highest in the RS and RTS. The major free amino acids in all samples were glutamic acid, lysine, leucine, and arginine. Sixty kinds of volatile flavor compounds were identified from all samples; the majority of which were 21 alcohols, 14 hydrocarbons, 5 esters, and others identifies as acids, ketones, and aldehydes.

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The Role of Carbon Metabolism Repressor CRE in the Regulation of Cellulase Produced by Rhizopus stolonifer

The Role of Carbon Metabolism Repressor CRE in the Regulation of Cellulase Produced by Rhizopus stolonifer

Optimization of the process for biodiesel production using a mixture of immobilized Rhizopus oryzae and Candida rugosa lipases.

In this study, the enzymatic process for biodiesel production was optimized using a mixture of immobilized Rhizopus oryzae and Candida rugosa lipases. The optimal temperature and agitation speed for biodiesel production were 45oC and 300 rpm, respectively. The optimal ratio of R. oryzae and C. rugosa lipases in the mixture was 3:1 (w:w). When 3mmol of methanol was the initial reaction medium and 3mmol of methanol was added every 1.5 h during biodiesel production, biodiesel conversion was over 98% at 4 h. In addition, when the immobilized lipase mixture was reused, biodiesel conversion exceeded 80% after 5 reuses.

Detection of Mycoflora and Aflatoxin B1 in the Seeds of Inodorous Melons (Cucumis melo L.)

Twenty-two seed samples of inodorous melons, collected from the areas of Peshawar, Swabi, Tordher, Fatu-chuk, Mardan, Karachi, Islamabad, Ghotki, and Mandibahauddin, yielded 75 species of 36 fungal genera, isolated through ISTA (International Seed Testing Association) techniques. The agar plate method was chosen as being best for the qualitative and quantitative isolation of fungi, followed by the standard blotter method. The agar plate method yielded 64 species of 29 genera, while the blotter method yielded 24 species belonging to 14 genera. The deep-freezing method yielded only 2 species belonging to 2 genera. Aspergillus niger , followed by A. flavus , Chaetomium globosum , and Rhizopus stolonifer were the most dominant fungi in all 3 methods used. Forty species belonging to 25 genera had not been previously reported from Pakistan. Seven seed samples, which were highly infected with fungi, were grown in test tube slants, included samples from Tordher (1), Ghotki (1), Mandibahauddin (1), Karachi (2), Islamabad (1), and Fatu-chuk (1). Aspergillus flavus was the most dominant fungi, causing pre-emergence rot of seedlings. Fusarium oxysporum caused 3.6 % of seedling deaths after 10 - 12 days of incubation. Seed samples from Islamabad, Mandibahauddin, and Swabi were highly infected with A. flavus . The level of aflatoxin B 1 estimated through CD-ELISA for the 3 samples was 32.64 ppb (Swabi), 11.48 ppb (Islamabad), and 7.30 ppb (Mandibahauddin), respectively, of which the seed sample from Swabi contained the highest level of aflatoxins. Surface sterilization of seeds with 1 % Calcium hypochlorite (Ca (OCl) 2 )greatlyreduced the incidence of both saprophytic and superficial pathogenic fungi. doi: 10.14456/WJST.2016.3

FIRST REPORT OF RHIZOPUS ORYZAE CAUSING FRUIT ROT OF CITRUS MEDICA L. IN PAKISTAN

Citrus medica, commonly known as Otroj, is a member of the family Rutaceae that contains important nutrients (Al-Yahya et al., 2013). In a survey from September to October 2014, C. medica fruits showing brown, wrinkled, sunken and dark lesions and decayed tissues that extended into the center, were collected in Islamabad Capital Territory (Pakistan). As the disease progressed, the fruits rotted severely and collapsed. A fungus isolated from diseased fruits on Sabouraud dextrose agar (SDA) mediium had an initially white mycelium that, over time, turned grayish black with a net-like structure. The reverse of the colonies was light brown. This fungus resembled morphologically Rhizopus oryzae and was comprised of sporangia, apophysis, sporangiophores and rhizoids. It grew by extending the hyphae along the surface of the substrate and penetrated it with rhizoids. The ultimate identification as R. oryzae was achieved based on the comparative molecular analysis of the ITS1, ITS4 and 18SrRNA sequences. In particular, BLAST analysis revealed 100% similarity with R. oryzae strain LXM4 (GenBank accession No. GQ220706.1) and 99% similarity with R. oryzae isolate F750 (KM249084.1), respectively. To prove Koch’s postulates, mycelial plugs (5-mm diameter) were placed on superficially wounded surface-sterilized C. medica fruits, all of which developed lesions after seven days at 27°C. R oryzae was consistently re-isolated from symptomatic fruits. No infection was observed on wounded but non-inoculated controls. To our knowledge, this is the first report of R. oryzae causing fruit rot of C. medica in Pakistan.

Effect of industrial tannery effluent on soil fungi and fungal protease/cellulase activity on modified rice husk /modified sawdust medium (MRHM/MSDM)

The release of unprecedented tannery effluents into agricultural fields constitutes danger to land fill and nutrient cycling as well as organic matter processing. In the present study, tannery effluent discharged soil (polluted landfill), undischarged soil (control) and effluent discharged (waste) were collected from the surrounding areas of tannery industry. The physico-chemical and biological properties and soil protease / cellulose were examined. The study shows that the value obtained from the colour, odour, pH, electrical conductivity and water holding capacity of the polluted soil was black, foul odour, 5.12, 0.72 µMhos cm-1 and 0.51 mg/l, respectively. In chemical parameters, organic matter, total nitrogen phosphorus and potassium have the following values: 8.2, 1.2, 0.15 and 0.39% respectively. In all ramifications, the polluted soils showed higher values than the control except that of potassium. The soil protease/ cellulose activities of the selected fungal were observed on different media (modified rice husk, modified saw dust and on control liquid media respectively). The activities were found to be higher on MRHM and MSDM (2.81 and 1.82 IU/ml) at maximum of 45 days than the control liquid media (1.23 IU/ml) at maximum of 15 days; they decreased to 0.312 IU/ml at 30 days. It was found that Rhizopus nigricans exhibited the highest cellulase activity (2.81 IU/ml) followed by Aspergillus niger (1.82 IU/ml) and the least Penicillium species (0.98 UI/ml) respectively. Key words: Protease/Cellulase, Rhizopus, Aspergillus, Penicillium solid state/submerge fermentation, tannery waste and contaminated soil.

Evaluation of different treatment on the occurrences of seed borne fungi of Mungbean Vigna radiata (L.) Wilczek seed

The efficacy of different treatment measures viz., corbendazim, Benomyle, Vitavax, Neem, Garlic, Trichoderma harzianum and Trichoderma viride were evaluated for the occurrences of seed borne fungi viz., Aspergillus spp, Penicillium spp, Alternaria alternata, Rhizopus and Fusarium spp which were isolated from two genotype of Mungbean viz., HUM-4 and HUM-12, from, 180 and 360 days period of storage. Both genotypes were taken from the Department of Genetics and Plant Breeding, Institute of Agricultural Science, B.H.U Varanasi. All treatments were found to significantly reduce the incidence of seed borne fungi but did not completely control it. The results showed that the incidence of seed borne fungi was found to be significantly declined when seeds were treated with different treatments but did not completely control it. Seed treated with mungbean seed showed least incidence. Due to an increase in storage period, efficacy of different treatment against seed borne fungi was found to be declined. After 180 days period of storage, effect of treatment was found to be intermediate. Least effect of treatment was shown at 360days period of storage due to an increase in the number of fungal population. Among all treatment, Benomyle, Corbendazim and Vitavax showed minimum occurrences against all fungi followed by Neem, Garlic and T. harzianum. Key words: seed borne fungi, Pulses, mungbean.

Adsorption-Desorption of Heavy Metal Ions

Adsorption and desorption studies on different types of adsorbents, including natural materials such as teak tree bark powder, rice husk, natural bentonite, different algae like Ecklonia maxima, Escherichia coli, Ascophyllum nodasum, Rhizopus nigricans, Cladophora fascicularis, goethite and soils of three nuclear power plant and artificial materials such as Fe oxide-coated sand, goethite pretreated with phosphate, dithizonemodified sodium trititanate whisker, modified nanometre sized TiO 2 , Chromosorb 102 resins and poly(m-phenylenediamine) are summarized. The kinetics, thermodynamics, sorption/desorption mechanism of different metal ions on different adsorbents under different experimental conditions are discussed. It is found that desorbing agent is greatly dependent on the adsorbate used. All the metal ions are desorbed using acids like HCl, HNO 3 and H 2 SO 4 in most of the cases, except Cr(VI). EDTA can be used to remove Pb 2+ and Zn 2+ in addition to acids. Since Cr(VI) is present in anionic form; it can be eliminated from the loaded adsorbents using bases like NaOH, Na 2 CO 3 or NaHCO 3 .

Survey of Fungi in Foodstuffs Stored in ASC Warehouses in Assam Region

The paper describes the isolation and characterisation of various fungi present in common foodstuffs stored in Army warehouses located in hot humid climate of Assam. Fungal contamination in the food commodities is highest in the rainy season and lowest in winter. Among the fungi isolated, Aspergillus niger, A. Fumigatus, Rhizopus nigricans and species of Mucor and Penicillium were found in all the samples analysed. Amongst these, members of Aspergillus dominated in the rainy season and Penicillium. Rhizopus nigricans was predominant in the winter months.

Yield of Fumaric Acid from Different Carbohydrates by Stationary Surface Culture Method

Studies on the yield of fumaric acid by Rhizopus arrhizus and Bhizopus nigricans using glucose, sucrose, xylose,cane molassess and bagasse hydrolysate either alone or in combination with glucose were undertaken. Thirty three and 26 per cently yield of fumaric acid were obtained from 12 and 10 per cent glucose media respectively, in 15 days at 33 degree calcius by stationary surface culture method. Higher yields of fumaric acid were obtained from glucose using R. arrhizus. Ability of this organism to produce fumaric acid from media containing (i) 50:50 glucose and deionized bagasse,hydrolysate (ii) deionized bagasse hydrolysate, and (iii) clarified cane molasses was investigated. A 7 per cent yield of fumaric acid was obtained from 50:50 glucose and deionized bagasse hydrolysate medium. In the case of xylose good growth of the fungus was obtained but no fumaric acid was produced. These studies have indicated that R. arrhizus is not able to utilize pentose sugars.

Screening, identifying and medium optimization of a lipase-producing filamentous fungus from soil for high chiral resolution of 1-phenylethanol

The kinetic resolution of racemates by biocatalysis is one of the major routes to manufacture optically pure compounds. Lipase-producing microorganisms were screened from soil for chiral resolution of 1-phenylethanol in the study. One microorganism with high chiral resolution ability was isolated and identified as Rhizopusstolonifer by the sequence similarity analysis and construction of phylogenetic tree. The media for the microorganism were optimized using Plackeet-Burman, Steepest Ascent and Box-Benhnken experiments. After optimization, the composition of the optimized medium used for lipase production was as follows: soluble starch (7.60 g/L), yeast extract (22.59 g/L), K2HPO4 (5.55 g/)L, NH4Cl (1.80 g/L), MgSO4·7H2O (2.40 g/L), NaCl (1.00 g/L), olive oil (25.00 mL/L), Tween-80 8.00 (mL/L), pH 4.59, and the lipase activity increased nearly by 2.04-fold, from 0.46 to 1.40 U/mL. The optimization was significant for the isolation and purification of the lipase and for the research of enzymatic characteristics. Key words: Screening, lipase, identification, Rhizopus stolonifer; optimization, 1-phenylethanol.

Influence of the Oil Pequi in the Growth Mycelial and Sporulation of Colletotrichum Musae and Growth Micelial Of Rhizopus sp. in vitro.

Abstract: The anthracnose caused by Colletotrichum musae and soft rot caused by Rhizopus sp are post-harvest diseases that influenced quality of exported fruits. To control these diseases fungicides are used, but in light of these waste products in the fruit and the environment, alternative control methods such as using biofungicides have been studied. The objective of this study was to evaluate the effect of pequi oil on mycelia growth and sporulation of Colletotrichum musae and mycelia growth of Rhizopus sp. in vitro. The oil was added in aliquots of 5, 10, 15, 20, 25, and 50L in the center of Petri dishes containing approximately 15mL of Potato-Dextrose-ar (PDA) and distributed over the surface of the medium with Drigalskys handle. After 24 hours, a disc of 8mm diameter from mycelium of fungi was peaked to the center of the plates. As a control, were used Petri dishes containing only PDA. Five replicates were used for each aliquot. After analysis, it was concluded that the pequi oil is ineffective for controlling these pathogens because induced mycelium growth and sporulation. Key Words : Phytopathogens, alternative control, anthracnose, soft rot

Antifungal activities of essential oils from some Iranian medicinal plants against various post harvest moulds

The potential antifungal effects of the essential oils and components of Thymus vulgaris L.,Thymus migricus Klokov and Desj-Shost., Thymus koschyanus Boiss., Mentha spicata L.,Mentha pulegium L., and Satureja mutica Fisch and C.A. (Lamiaceae) were investigated against four food poisoning and plant pathogens. The essential oils were obtained by hydro distillation of dried plant materials and their composition was determined by gas chromatograph and mass spectrometer (GC-MS) in previous studies. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the oils and their components were determined by dilution assays. Thymus species showed very strong antifungal activities. Culture Potato Dextrose Agar (PDA) media with all oil-enrichment resulted in significant (P≤0.01) reduction on subsequent colony development of Rhizopus oryzae (up to 28%) at 100 ppm; Botrytis cinerea (up to 100%); Penicillium expansum (up to 69%) at 100 ppm and Rhizopus stolonifer (up to 56%) at 100 ppm. Among studied fungi, B. cinerea and P. expansum were the most sensitive pathogens treated with MICs of 100 and 150 ppm, respectively. Differences between high MICs and MFCs of M. spicata and T. vulgaris and low MICs and MFCs of T. koschyanus and T. migricus inhibiting the growth and colony development of tested fungi correlated with simultaneous high concentration of thymol and carvacrol in species of T. koschyanus, T. migricus, M. pulegium and S. mutica. It is concluded that essential oils of Thymus, Satureja and Mentha species possess great antifungal potential and could be used as natural preservatives and fungicides. Key words: Antifungal activity, plant pathogens, essential oils, fungal growth, Lamiaceae family.

Biotransformation of γ-decalactone and γ-caprolactone by rhizopus sp. using castor and linseed oils

Biotransformation of γ-decalactone and γ-caprolactone by rhizopus sp. using castor and linseed oils

Cutaneous and Mucosal Mucormycosis: Don't Be Misled

Mucormycosis, or zygomycosis, refers to opportunistic infection of the skin by fungi of the family Mucoraceae (genera Rhizopus, Mucor, and Absidia).

Antimicrobial properties of skin mucus from four freshwater cultivable Fishes (Catla catla, Hypophthalmichthys molitrix, Labeo rohita and Ctenopharyngodon idella)

The fishes are living in the medium rich in pathogenic microbes. The mucus secreted by the skin of fish showed more antimicrobial properties. The mucus collected from the two exotic fishes and two indigenous fishes were tested against the five pathogenic bacteria (Klebsiella pneumonia, Vibrio cholerae, Salmonella typhi, Escherichia coli andPseudomonas aeruginosa) and five pathogenic fungi namely (Mucor globosus, Rhizopus arrhizus, Candida albicans, Aspergillus flavus and Aspergillus niger). The fishes are living in media rich in pathogenic microbes which secrete substances against them. The mucus secreted by the skin of fish showed more antimicrobial properties. More antibacterial and antifungal activity were observed in an indigenous fishes (Catla catla and Labeo rohita) than exotic fishes (Hypophthalmichthys molitrix and Ctenopharyngodon idella). Key words: Antibacterial, antifungal, fish mucus, exotic, indigenous fish.

Determination of antimicrobial potentialities of different solvent extracts of the medicinal plant: Phyllanthus amarus Schum. and Thonn.

The antimicrobial efficiency of Phyllanthus amarus Schum. and Thonn., medicinal plants (leaf extracts), was examined using Methanol, Ethanol, Petroleum ether. and water, as solvents and tested against eight human pathogens like Bacteria: Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, Fungi: Aspergillus niger, Aspergillus flavus, Fusarium oxisporum, and Rhizopus stolonifer, using the agar well-diffusion method and minimum inhibitory concentration. All the plants showed significant activity against all pathogens, but the alcoholic extract of P. amarus showed the maximum zone of inhibition and minimum inhibitory concentration against all the microorganisms. The minimum zone of inhibition and comparatively greater inhibitory concentration were determined in petroleum ether, and the aqueous extract of P. amarus showed less antimicrobial activity against all the experimental strains. The alcoholic extracts of these plants could be a possible source of obtaining new and effective herbal medicines to treat infections, hence, it justified the ethnic use of P. amarus against various infectious diseases. Key words: Agar well well-diffusion method, antimicrobial activity, medicinal plants, minimum bactericidal concentration, minimum fungicidal concentration, minimum inhibitory concentration, Phyllanthus amarus

Fungal and bacterial contaminants of six spices and spice products in Ghana

The microbiological quality of two spices (aniseed and rosemary) and spice products (maggi onion cube, maggi shrimp cube, royco shrimp cube, royco beef cube) have been studied using conventional mycological techniques. The presence of moulds and yeast was compared on three media DRBC, OGYE, and PDA at 30°C incubated for 5 days. The species of fungi that were isolated from the raw spices and spice products tested belonged to eight (8) genera. (Absidia, Aspergillus, Cladosporium, Fusarium, Rhizopus, Penicillium, Neurospora, Eurotium,). Aspergillus species (A. flavus, A. fumigatus, A. alutaceus, A. niger, A. sulphureus) were the more predominant species isolated. A. flavus was the most frequently isolated fungal species in all the spices on all the three media on which growth was compared. Aniseed harboured fungal population ranging from 1.50 log10 CFU/g sample to 1.88 log10 sample; maggi onion cube 0.90 – 1.54 log10 CFU/g sample; maggi shrimp cube 1.11 – 1.30 log10 CFU/g sample; royco shrimp cube; 1.0 – 1.08 log10 CFU/g sample and 1.19 – 1.31 log10 CFU/g sample in royco beef cube. The aflatoxin analysis showed that aflatoxins B1 , B2, G1,and G2 were not formed. The bacteria species isolated from the spices varied. The spices and spice products collectively harboured Aeromonas salmonicida, Enterobacter cloacae, Enterobacter amnigenus, Enterobacter agglomerans, Enterobacter sakazakii, Flavobacterium sp, Chromobacterium violaceum, Pseudomonas putida, Pseudomonas aeroginosa, Acinetobacter sp, Pseudomonas cepacia, Serratia plymuthica. The human health implications of these findings are discussed and future work recommended. Key words: Microbiological quality, spices, spice products, contaminants