Decomposition of plant litter is a fundamental ecosystem process that can act as a feedback to climate change by simultaneously influencing both the productivity of ecosystems and the flux of carbon dioxide from the soil. The influence of climate on decomposition from a postsenescence perspective is relatively well known; in particular, climate is known to regulate the rate of litter decomposition via its direct influence on the reaction kinetics and microbial physiology on processes downstream of tissue senescence. Climate can alter plant metabolism during the formative stage of tissues and could shape the final chemical composition of plant litter that is available for decomposition, and thus indirectly influence decomposition; however, these indirect effects are relatively poorly understood. Climatic stress disrupts cellular homeostasis in plants and results in the reprogramming of primary and secondary metabolic pathways, which leads to changes in the quantity, composition, and organization of small molecules and recalcitrant heteropolymers, including lignins, tannins, suberins, and cuticle within the plant tissue matrix. Furthermore, by regulating metabolism during tissue senescence, climate influences the resorption of nutrients from senescing tissues. Thus, the final chemical composition of plant litter that forms the substrate of decomposition is a combined product of presenescence physiological processes through the production and resorption of metabolites. The changes in quantity, composition, and localization of the molecular construct of the litter could enhance or hinder tissue decomposition and soil nutrient cycling by altering the recalcitrance of the lignocellulose matrix, the composition of microbial communities, and the activity of microbial exo‐enzymes via various complexation reactions. Also, the climate‐induced changes in the molecular composition of litter could differentially influence litter decomposition and soil nutrient cycling. Compared with temperate ecosystems, the indirect effects of climate on litter decomposition in the tropics are not well understood, which underscores the need to conduct additional studies in tropical biomes. We also emphasize the need to focus on how climatic stress affects the root chemistry as roots contribute significantly to biogeochemical cycling, and on utilizing more robust analytical approaches to capture the molecular composition of tissue matrix that fuel microbial metabolism.
Nature relies on a wide range of enzymes with specific biocatalytic roles to carry out much of the chemistry needed to sustain life. Enzymes catalyze the interconversion of a vast array of molecules with high specificity—from molecular nitrogen fixation to the synthesis of highly specialized hormones and quorum‐sensing molecules. Ever increasing emphasis on renewable sources for energy and waste minimization has turned enzymes into key industrial workhorses for targeted chemical conversions. Modern enzymology is central to not only food and beverage manufacturing processes but also finds relevance in countless consumer product formulations such as proteolytic enzymes in detergents, amylases for excess bleach removal from textiles, proteases in meat tenderization, and lactoperoxidases in dairy products. Herein, we present an overview of enzyme science and engineering milestones and the emergence of directed evolution of enzymes for which the 2018 Nobel Prize in Chemistry was awarded to Dr. Frances Arnold.
more » « less- Award ID(s):
- 1703274
- NSF-PAR ID:
- 10372921
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- AIChE Journal
- Volume:
- 66
- Issue:
- 3
- ISSN:
- 0001-1541
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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