Green conversion of agroindustrial wastes into chitin and chitosan by Rhizopus arrhizus and Cunninghamella elegans strains.
This article sets out a method for producing chitin and chitosan by Cunninghamella elegans and Rhizopus arrhizus strains using a green metabolic conversion of agroindustrial wastes (corn steep liquor and molasses). The physicochemical characteristics of the biopolymers and antimicrobial activity are described. Chitin and chitosan were extracted by alkali-acid treatment, and characterized by infrared spectroscopy, viscosity and X-ray diffraction. The effectiveness of chitosan from C. elegans and R. arrhizus in inhibiting the growth of Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica, Escherichia coli and Yersinia enterocolitica were evaluated by determining the minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC). The highest production of biomass (24.60 g/L), chitin (83.20 mg/g) and chitosan (49.31 mg/g) was obtained by R. arrhizus. Chitin and chitosan from both fungi showed a similar degree of deacetylation, respectively of 25% and 82%, crystallinity indices of 33.80% and 32.80% for chitin, and 20.30% and 17.80% for chitosan. Both chitin and chitosan presented similar viscosimetry of 3.79-3.40 cP and low molecular weight of 5.08×10³ and 4.68×10³ g/mol. They both showed identical MIC and MBC for all bacteria assayed. These results suggest that: agricultural wastes can be produced in an environmentally friendly way; chitin and chitosan can be produced economically; and that chitosan has antimicrobial potential against pathogenic bacteria.
Post-Graduation Program in Biological Sciences, Federal University of Pernambuco, Recife, PE 50670-420, Brazil. quelberger@hotmail.com.
Lúcia Raquel Ramos
LR
Berger
Department of Tropical Medicine, Center of Health Sciences, Federal University of Pernambuco, Recife, PE 50670-420, Brazil. thayzastamford@yahoo.com.br.
Thayza Christina Montenegro
TC
Stamford
Department of Tropical Medicine, Center of Health Sciences, Federal University of Pernambuco, Recife, PE 50670-420, Brazil. thayzastamford@yahoo.com.br.
Thatiana Montenegro
TM
Stamford-Arnaud
Post-Graduation Program in Development and Environment, Federal University of Paraíba, Campus 1, João Pessoa, PB 58051-900, Brazil. pohlux@gmail.com.
Sergio Roberto Cabral
SR
de Alcântara
Nucleus of Research in Environmental Science and Biotechnology (NPCIAMB), Catholic University of Pernambuco, Recife, PE 50050-590, Brazil. antoniocardoso2000@yahoo.com.br.
Antonio Cardoso
AC
da Silva
Post-Graduation Program in Biological Sciences, Federal University of Pernambuco, Recife, PE 50670-420, Brazil. antoniocardoso2000@yahoo.com.br.
Adamares Marques
AM
da Silva
Nucleus of Research in Environmental Science and Biotechnology (NPCIAMB), Catholic University of Pernambuco, Recife, PE 50050-590, Brazil. elesbao@unicap.br.
Aline Elesbão
AE
do Nascimento
Nucleus of Research in Environmental Science and Biotechnology (NPCIAMB), Catholic University of Pernambuco, Recife, PE 50050-590, Brazil. galba_takaki@yahoo.com.br.
Galba Maria
GM
de Campos-Takaki
D001673:Biodegradation, Environmental; D018533:Biomass; D002686:Chitin / Q000737:chemistry / Q000378:metabolism*; D048271:Chitosan / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D020093:Cunninghamella / Q000378:metabolism*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D007220:Industrial Waste; D008826:Microbial Sensitivity Tests; D012233:Rhizopus / Q000378:metabolism*
D007220:Industrial Waste; D002686:Chitin; D048271:Chitosan