Abstract:
The present research delves into the intricacies of isolating and characterizing an amylolytic lactic acid bacterium, specifically identified as Lactobacillus plantarum, extracted from cassava roots. The strain, denoted as L. plantarum A6, demonstrated remarkable growth on starch, with its amylolytic enzyme identified as α-amylase exhibiting optimal activity at pH 5.5 and a temperature of 65 °C. This study explores the potential application of the identified strain as a fermentation starter for gari production, shedding light on alterations in fermentation patterns and the enhanced production of lactic acid.
Introduction:
Traditional cassava-based fermented foods play a pivotal role in various cultures, and the involvement of lactic microflora in their preparation has long been acknowledged. However, a comprehensive understanding of the microflora’s functions, ranging from food preservation to eliminating cyanogenic compounds and enhancing organoleptic qualities, remains elusive. This study endeavors to address these gaps by isolating and characterizing an amylolytic lactic acid bacterium, with a focus on its potential implications for improving control over natural fermentation processes, particularly in the context of cassava-based products like gari.
Methods:
The isolation and identification procedures involved a meticulous process, including immersing peeled cassava roots in rainwater, random sampling, and subsequent microbial analysis. Identification criteria encompassed the production of lactic acid, homolactic or heterolactic characteristics, morphological features, and growth conditions. To establish a robust foundation for comparison, three reference strains and JP2 medium were employed for culture and physiological studies.
Results and Discussion:
Efforts in isolating strains culminated in the identification of L. plantarum A6, an amylolytic strain showcasing superior starch hydrolysis capabilities. Growth kinetics on both glucose and starch media exhibited comparability to established reference strains. The purification and characterization of the extracellular α-amylase yielded insights into its optimal conditions, marking a distinction from other lactic acid bacterial amylases.
Furthermore, the purification process suggested a potential aggregation of a 50-kDa amylase, drawing parallels with previous observations in Bacillus subtilis. This insight prompts intriguing hypotheses about the evolutionary relationship between these microorganisms and calls for further investigation.
Application to Cassava Fermentation:
The practical application of the study in cassava fermentation revealed compelling outcomes. Inoculation with L. plantarum A6 resulted in accelerated pH decline, heightened lactic acid production, and a discernible shift from heterofermentation to homofermentation. These findings underscore the strain’s potential to not only enhance the quality and uniformity of cassava-based fermentation processes but also to exert influence in shaping the organoleptic qualities of the final product.
Conclusion:
In conclusion, this research emerges as a pivotal contribution to the realm of lactic acid bacteria, unraveling a novel amylolytic strain, L. plantarum A6, isolated from cassava roots. The study not only enriches our understanding of the taxonomy of lactic acid bacteria but also accentuates the potential significance of this strain in the context of starch-based fermentation processes. As we delve deeper into the implications of its unique enzymatic properties, a myriad of opportunities for further exploration beckon. Future investigations are warranted to unlock the full spectrum of applications and ramifications of this newly discovered amylolytic lactic acid bacterium.