Interactions of Bacteria and Fungi on Decomposing Litter: Differential Extracellular Enzyme Activities – Article Example

Critique and Key Learnings from the Journal Article “Interactions of Bacteria and Fungi on Decomposing Litter: Differential Extracellular Enzyme Activities”
The two major organisms responsible for degradation of plant litter in freshwater ecosystems are fungi and bacteria. However, the process of degradation and interface between the two organisms are yet to be established. Romani et al. conducted a study to compare the growth, enzyme production and synergistic or antagonistic interactions by both organisms (2006).
The research was done with fungi and a bacterial colony inoculated on Phragmite leaves, which were either sterilized or non-sterilized. Some colonies co-existed with each other, and some grew on their own. Thus, there were models with both bacterial and fungal colonies co-existing. The study recorded the individual and combined progress and effects of fungi and bacteria on plant litter for 61 days.
On their own, fungal colonies are highly capable of degrading and decomposing plant litter. Fungi are capable of decomposing different plant polymers, such as cellulose, hemicellulose and lignin. When it comes to decomposing plant litter present in lake and wetland ecosystems, fungal colonies are characterized by high microbial production in biomass (Kominkova et al., 2000).
In the early stages of decomposition, bacterial colonies are less important. Bacteria mainly decompose materials in standing water (Anesio et al., 2003). In these models, the key enzymes phenol oxidase and cellobiohydrolase, which aid in degradation of cellulose and lignin, were undetected.
In models where fungi and bacteria co-existed, synergistic and antagonistic effects were observed. Bacterial growth and metabolism were markedly increased within fungal colonies. However, this resulted in a decline or suppression of fungi growth and accumulation of biomass. The results showed that bacteria depend on the enzymatic activity produced by fungi, even as the former also suppress the growth of fungi.
Significance
This study focused on the individual and cumulative enzyme production and biomass of both fungal and bacterial colonies in a laboratory setting. Biomass is a renewable and sustainable energy source, which is important ecologically and economically.
If this study about enzymatic interaction could be replicated with miscanthus grass (as a research team at North Carolina State University have done with this proliferating cousin to sugarcane that provides excellent lignocellulosic biomass for bioethanol production) and agricultural waste, it would be of great use to the whole of mankind. Sharma-Shivappa et al. (2006) had already proven a process for hastening breakdown of lignin in high-carbohydrate non-food plants while Atalla et al (2007) had done much the same with extracting fermentable glucose out of the rich cellulose in corn stover. By fine-tuning the enzymatic stage with the Romani et al. findings, the world would be spared the specter of food supplies going to produce biofuel instead of feeding the hungry.
Recommendation
For future research, other factors such as season, pH and salinity of the aqueous medium and other environmental factors should be considered to test if the same effects can be produced in vivo. It would also be helpful to study if the same species of fungi and bacteria can produce the same effect using other plant litter with a different cell wall composition.
Definitions
Particulates are subdivisions of solid matter which are suspended in either gas or liquid. This can either be man-made or natural. Particulates are produced through decomposition or degradation by an enzyme.
Decomposition is when organic materials are broken down into smaller or simpler forms. This aids in recycling finite materials present within organisms which occupy a limited space within a biome. Hence, decomposition is the process of degrading any material from previously living organism to its simplest form, so that another organism can utilize the same nutrients and materials that are remnants of the dead organism.
Biomass is material acquired from a previously-living or recently living organism such as plant waste, animal waste, or wood. In this case, “biomass” refers exclusively to plant litter which upon degradation can fire a steam engine (when methane is produced) and thus generate electricity. This is produced industrially by growing numerous types of plants such as corn, hemp, poplar, willow, and sugarcane. The plant used is unimportant when it comes to creating biofuel; however, it is important when it comes to processing raw materials, which explains the importance of understanding enzymatic reactions and interactions.
Phragmites is a perennial grass found within wetlands in temperate and tropical regions of the planet.
Hemicellulose is a matrix of polysaccharides such as arabinoxylans, which is usually present with cellulose in plant cell walls.
References
Anesio, A. M., P. C. Abreu, and B. A. Biddanda. 2003. The role of free and attached microorganisms in the decomposition of estuarine macrophyte detritus. Estuarine, Coastal, and Shelf Science, 56:197-201.
Atalla, R., Isogai, A. & Sugiyama, J. (2007). Structural chemistry of cellulose. London: CRC Press.
Kominkova, D., K. A. Kuehn, N. Busing, D. & Steiner, M (2004). Microbial biomass, growth, and respiration associated with submerged litter of Phragmitesaustralis decomposing in a littoral reed stand of a large lake. Aquatic Microbial Ecology, 22 (3) 271-282.
Romani, A.M., Fisher, H., Mille-Lindblom, C., & Tranvik, L.J. (2006). Interactions of bacteria and fungi on decomposing litter: Differential extracellular enzyme activities. Ecology, 87 (10): 2559-2569.