Assessment of Extracellular Beta-Galactosidase Production Potential of Fungi Isolated from Dairy Effluent.
ABSTRACT
Dairy wastewater is increasingly becoming an environmental concern. There is a widespread interest in the use of beta-galactosidase (EC 3.2.1.23) to hydrolyze lactose in milk and dairy products which aid in improving their functional and digestive properties.
An attempt was made to isolate fungi from dairy effluent using standard culture techniques. Physicochemical characteristics and proximate composition of the dairy effluent was analyzed.
The fungi isolated were subsequently screened using Ortho-nitrophenol-beta-D-galactopyranoside (ONPG) discs method for potential to produce beta-galactosidase.
The isolate showing beta-galactosidase activity was selected and used to produce beta-galactosidase under submerged fermentation using the dairy effluent as a substrate.
A total of nine (9) fungi were isolated from the dairy effluent belonging to the Genera Aspergillus, Rhizopus, Rhizomucor and Penicillium with Aspergillus having the highest frequency of occurrence (67%).
Physicochemical analyses of the raw dairy effluent revealed the effluent had a pH of 6.8 (±0.20), electrical conductivity of 645μs/cm (±1.00) and total dissolved solids of 324mg/L (±2.00).
TABLE OF CONTENTS
Contents Page No.
Cover Page
Title page……………………….i
Declaration ………………….. ii
Certification ……………….. iii
Acknowledgements ……….. iv
Abstract ……………………….v
Table of Contents …………… vi
List of Tables ………………..x
List of Figures ………………. xi
List of Appendices ……. xii
CHAPTER ONE
1.0 INTRODUCTION………………… 1
1.1 Background of the Study …… 1
1.2 Statement of Research Problem………. 3
1.3 Justification of the Study ………… 4
1.4 Aim of the Study……………. 6
1.5 Objectives of the Study ………….. 6
CHAPTER TWO
2.0 LITERATURE REVIEW ………………… 7
2.1 Dairy Industry …………….. 7
2.2 Lactose Hydrolysis ………………… 10
2.2.1 Chemical lactose hydrolysis…21
2.2.2 Enzymatic lactose hydrolysis……..22
CHAPTER THREE
3.0 MATERIALS AND METHOD …….. 36
3.1 Collection of Sample …………….. 36
3.2 Isolation and Characterization of Fungi …………… 36
3.2.1 Preparation of media …………… 36
3.2.2 Serial dilution ………………………… 36
3.2.3: Culture of fungi………………………. 37
CHAPTER FOUR.
4.0 RESULTS ………………. 47
4.1 Isolation and Characterization of Fungal Isolates from Dairy Effluents …….. 47
4.2 Distribution of fungi isolated from raw dairy effluent …………. 47
4.3 Physicochemical Analyses of Raw Dairy Effluent ……………. 47
4.4 Proximate Analysis of Treated Dairy Effluent……….. 51
4.5 Screening of Fungal Isolates for Production of Extracellular Beta-Galactosidase using ONPG Discs … 51
CHAPTER FIVE
5.0 DISCUSSION …………….. 54
5.1 Isolation and Characterization of Fungal Isolates from Dairy Effluent……… 54
5.2 Physicochemical Analyses of Raw Dairy Effluent ……….. 55
5.3 Proximate Composition of the Sterile Dairy Effluent ……… 59
5.4 Screening of Fungal Isolates for Extracellular Beta-Galactosidase Production ……… 60
5.5 Production of Extracellular Beta-galactosidase by Rhizopus spp. under Submerged Fermentation using Sterilized Dairy Effluent as Substrate ………. 61
CHAPTER SIX
6.0 CONCLUSION AND RECOMMENDATION ………… 62
6.1 Conclusion ………………………… 62
6.2 Recommendations ………………. 62
REFERENCES…………………….. 64
APPENDIX …………………………. 78
INTRODUCTION
1.1 Background of the Study
A dairy is a business enterprise established for the harvesting of animal milk, mostly from cows or goats, but also from buffalo, sheep, or camels for human consumption (Sreemoyee and Priti, 2013).
Among the major industries in the world, dairy is one of the industries producing wastewater rich in organic matter and thus leading to creation of odorous and high Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) containing water (Harush et al., 2011).
Dairy industry produces washwater (a high strength waste) as a byproduct of cleaning the milking facility after each milking event to maintain sanitary operations.
Generally, dairy wastes contain large quantities of milk constituents such as casein, lactose, fat, inorganic salts besides detergents and sanitizers, fresh water and sometimes animal waste which contribute largely towards high BOD and COD (Marwaha et al., 2001; Sweet, 2009).
REFERENCES
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Adhikari, T. B. and Shrestha, S.M. (1989). Laboratory Manual of Plant Pathology. Institute of Agriculture and Animal Science, Nepal, India.
Ahmed, S., Kattimani L., Divatar M., Gajare S., Shivalee A., Farheen A. and Irfana M. (2016). Optimization of Lactase Production under Submerged Fermentation by Lactobacillus sp. KLSA 22. International Journal of Pure and Applied Biosciences, 4(4): 212-220
Akinola, G. E., Adebayo T. B., Olonila O. T. (2012). Screening and Production of β- galactosidase by Trichoderma species. Nature and Science, 10(12):265-270.
Alikkunju, A. P., Sainjan, N., Silver, R., Joseph A., Rahiman M., Anthony C. A., Kumaran C. R. and Hatha M. (2016). Screening and Characterization of Cold-Active β-galactosidase Producing Psychrotrophic Enterobacter ludwigii from the Sediment of Arctic Fjord. Journal of Applied Biochemistry and Biotechnology, 180: 477-490.
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