Lignin is a major component of soil organic matter and also a rich source of carbon dioxide in soils. However, because of its complex structure and recalcitrant nature, lignin degradation is a major challenge. Efforts have been made from time to time to understand the lignin polymeric structure better and develop simpler, economical, and bio-friendly methods of degradation. Certain enzymes from specialized bacteria and fungi have been identified by researchers that can metabolize lignin and enable utilization of lignin-derived carbon sources. In this review, we attempt to provide an overview of the complexity of lignin’s polymeric structure, its distribution in forest soils, and its chemical nature. Herein, we focus on lignin biodegradation by various microorganism, fungi and bacteria present in plant biomass and soils that are capable of producing ligninolytic enzymes such as lignin peroxidase (LiP), manganese peroxidase (MnP), versatile peroxidase (VP), and dye-decolorizing peroxidase (DyP). The relevant and recent reports have been included in this review.

Ascorbic acid is a bacteriostatic agent; one of the many ways by which ascorbic acid hampers bacterial growth is by the production of hydrogen peroxide, which further converts into hydroxyl free radicals. Certain amino acids can counteract the inhibitory effect of hydroxyl free radicals by checking their oxidizing effect. Though ascorbic acid is bacteriostatic in nature, it facilitates prokaryotic respiration by decarboxylation. This study was carried out to understand how microbes from different horizons of the forest soil respond to the addition of a bacteriostatic agent (ascorbic acid) and growth promoting agent (amino acids), with respect to the soil respiration. We observed that the addition of either ascorbic acid or a combination of it with amino acid consistently results in increased soil respiration, and this increase is different for different soil types depending on soil composition and origin. Furthermore, we also found that beta alanine-induced maximum respiration in basic soils and L-glutamic in acidic soils. This study is significant because it can be used to explain how a strong reducing sugar, i.e., ascorbic acid, affects the soil respiration mediated via soil microbes. To the best of our knowledge, it is the first report that demonstrates the effect of bacteriostatic and the growth promoting agent together on microbe-mediated soil respiration.

Background: In community-dwelling older adults, slow gait speed is linked to falls; however, little is known about the use of gait speed to predict falls in nursing home residents. The prevalence of risk factors for falls in nursing home residents is multifactorial. Objective: The purpose of this study was to examine the relationship between falls and multiple factors such as age, sex, gait speed, mobility device, fear of falling, cognitive function, medication, and environmental causes in a nursing home setting. Material and Methods: Participants were recruited from a nursing home. Independent variables such as age, sex, gait speed for 40 feet, use of a mobility device, fear of falls, cognitive function, medication, and environmental causes of falls were measured and recorded. The dependent variable was falls. Participants were followed-up for a period of six months for falls. Falls were documented from the computerized medical records at the facility. Results: Five of the 16 participants had falls in the follow-up period. Exact logistic regression, bivariate analysis, showed no significant relationship between falls and the independent variables of age, sex, gait speed, mobility device, fear of falls, cognitive function, and medication. More than 30% of recorded falls had an environmental cause, which was significant at p = 0.0005. Conclusion: Environmental causes had a significant relationship with falls in nursing home participants. Environment hazard monitoring is therefore important to ensure the safety of nursing home residents.