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Glycolipids produced and secreted by oleaginous yeasts are renewable compounds with important physico‐chemical properties, and multiple biological and industrial applications. The large‐scale production of these compounds has been limited by high production costs and low yields. The sophorolipid‐producing yeast Pseudohyphozyma bogoriensis may possess the ability to grow in fermentation systems using carbon substrates deriving from inexpensive lignocellulosic biomass, while simultaneously secreting high value biomaterials. In this study, comparative analyses between different cellulose‐derived carbon sources including glucose, cellobiose, and sodium carboxymethyl cellulose confirmed the ability of P. bogoriensis to grow and accumulate glycolipids using these substrates. On a dry weight basis, the highest yields of about 4% (wt/wt) glycolipids were obtained when cellobiose was supplemented at 10 g/L in shake‐flask fermentations. When the unconventional carbon substrate sodium carboxymethyl cellulose was supplemented, cultures exhibited a lower glycolipid yield of 0.3% (wt/wt), but the dry weight was higher compared to other substrates. Analytical analyses using various chromatography methods confirmed the chemical profiles, whereas both monoacetylated and diacetylated sophorolipid forms with 22 carbon long‐chain hydroxy fatty acid were identified in all glycolipid extracts. Surface tension (ST) and critical micelle concentration (CMC) measurements showed that glycolipids produced on cellulose‐derived substrates exhibited similar or even superior physical properties compared with glucose. Furthermore, availability of the yeast genome sequences facilitated the identification of putative genes that may be involved in cellulose hydrolysis (e.g., cellulase‐like). Information on genomic and metabolic pathways is a prerequisite for trait improvement toward increasing the production of high value biomaterials. [ABSTRACT FROM AUTHOR]

Climatic fluctuations, temperature extremes, and water scarcity are becoming increasingly unpredictable with the passage of time. Such environmental atrocities have been the scourge of agriculture over the ages, bringing with them poor harvests and threat of famine. Rice production, owing to its high-water requirement for cultivation, is highly vulnerable to the threat of changing climate, particularly prolonged drought and high temperature, individually or in combination. Amidst all the abiotic stresses, heat and drought are considered as the most important concurrent stressors, largely affecting rice yield and productivity under the current scenario. Such threats heighten the need for new breeding and cultivation strategies in generating abiotic stress-resilient rice varieties with better yield potential. Responses of rice to these stresses can be categorized at the morphological, physiological and biochemical levels. This review examines the physiological and molecular mechanism, in the form of up regulation of several defense machineries of rice varieties to cope with drought stress (DS), high temperature stress (HTS), and their combination (DS-HTS). Genotypic differences among rice varieties in their tolerance ability have also been addressed. The review also appraises research studies conducted in rice regarding various phenotypic traits, genetic loci and response mechanisms to stress conditions to help craft new breeding strategies for improved tolerance to DS and HTS, singly or in combination. The review also encompasses the gene regulatory networks and transcription factors, and their cross-talks in mediating tolerance to such stresses. Understanding the epigenetic regulation, involving DNA methylation and histone modification during such hostile situations, will also play a crucial role in our comprehensive understanding of combinatorial stress responses. Taken together, this review consolidates current research and available information on promising rice cultivars with desirable traits as well as advocates synergistic and complementary approaches in molecular and systems biology to develop new rice breeds that favorably respond to DS-HTS-induced abiotic stress. [ABSTRACT FROM AUTHOR]