Jojoba - The Gold of Desert

Jojoba [Simmondsia chinensis (Link) Schneider] is evergreen, perennial and drought resistant shrub belongs to the family of Simmondsiaceae. It is a multipurpose oil seed crop mainly grown in desert regions of world. This plant has unique oil among plant kingdom which is chemically a liquid-wax. The liquid-wax is made up of an ester of long chain fatty acids and alcohols. The liquid-wax is unique in nature because have no traces of glycerine and easily modified via hydrolysis, hydrogenation, halogenation, sulfurization, phosphosulfurization and ozonization techniques. The main uses of liquid-wax in various industries like cosmetics, pharmaceuticals, petrochemicals and lubricants. It is a potential seed oil crop for desert region so it is well known as the gold of desert. The main purpose of this chapter is to review the complete information about this plant so that it can produce and utilized maximally. Moreover, the review focuses on biology, biogeography, physico-chemical properties of jojoba oil and propagation techniques of the plant of desert regions.

Syntrophy between fermentative and purple phototrophic bacteria for carbohydrate-based wastewater treatment

Fermentative chemoorganoheterotrophic bacteria (FCB) and purple photoorganoheterotrophic bacteria (PPB) are two interesting microbial guilds to process carbohydrate-rich wastewaters. Their interaction has been studied in axenic pure cultures or co-cultures. Little is known about their metabolic interactions in open cultures. We aimed to harness the competitive and syntrophic interactions between PPB and FCB in mixed cultures. We studied the effect of reactor regimes (batch or continuous, CSTR) and illumination modes (continuous irradiation with infrared light, dark, or light/dark diel cycles) on glucose conversions and the ecology of the process. In batch, FCB outcompeted (>80%) PPB, under both dark and infrared light conditions. In CSTR, three FCB populations of Enterobacteriaceae, Lachnospiraceae and Clostridiaceae were enriched (>70%), while Rhodobacteraceae relatives of PPB made 30% of the community. Fermentation products generated from glucose were linked to the dominant FCB. Continuous culturing at a dilution rate of 0.04 h-1 helped maintain FCB and PPB in syntrophy: FCB first fermented glucose into volatile fatty acids and alcohols, and PPB grew on fermentation products. Direct supply of carboxylates like acetate under infrared light enriched for PPB (60%) independent of reactor regimes. Ecological engineering of FCB- and PPB-based biorefineries can help treat and valorize carbohydrate-based waste feedstocks.

Assimilation and turnover rates of lipid compounds in dominant Antarctic copepods fed with 13 C-enriched diatoms

The study revealed species- and stage-specific differences in lipid accumulation of the dominant Antarctic copepods, the primarily herbivorous Calanoides acutus (copepodite stage V (CV), females) and the more omnivorous Calanus propinquus (females) storing wax esters and triacylglycerols, respectively, which were collected in summer (end of December). Feeding carbon-labelled diatoms to these copepods, 13 C elucidated assimilation and turnover rates of copepod total lipids as well as specific fatty acids and alcohols. The 13 C incorporation was monitored by compound-specific stable isotope analysis (CSIA). CV stages of C. acutus exhibited an intense total lipid turnover and 55% of total lipids were labelled after 9 days of feeding. By contrast, total lipid assimilation of female C. acutus and C. propinquus was lower with 29% and 32%, respectively. The major dietary fatty acids 16:0, 16:1(n − 7) and 20:5(n − 3) had high turnover rates in all specimens. In C. acutus CV, the high rates of the de novo synthesized long-chain monounsaturated fatty acids and alcohols 20:1(n − 9) and 22:1(n − 11) indicate intense lipid deposition, whereas these rates were low in females. The differences in lipid assimilation and turnover clearly show that the copepod species exhibit a high variability and plasticity to adapt their lipid production to their various life phases. This article is part of the theme issue ‘The next horizons for lipids as ‘trophic biomarkers': evidence and significance of consumer modification of dietary fatty acids'.

PROSPECTS FOR USING BIOTECHNOLOGICAL METHODS TO INCREASE THE POTENTIAL OF BEESWAX AS A STRUCTURAL OLEOGEL WAX

The characteristics of individual fractions of beeswax and their binary combinations, reflecting the potential for the formation of structural forming properties in food oleogels, have been studied. Increasing the efficiency of beeswax usage in oleogels can be achieved by biotechnological means to increase the content of free fatty acids and alcohols in its composition.

Biodegradation of polyvinyl alcohol by different dominant degrading bacterial strains in a baffled anaerobic bioreactor

Polyvinyl alcohol (PVA) is the main pollutant in printing and dyeing wastewaters. This pollutant exhibits great demand, poor biodegradability and refractory degradation. In this study, PVA wastewater treatment experiments were conducted in a stably operating baffled anaerobic bioreactor (ABR) by using simulated PVA wastewater. The PVA degradation pathway and mechanism of the mixed dominant PVA-degrading bacterial strains were identified through the analysis of their degradation products. From the results, we inferred that PVA was degraded in a stepwise process under the synergistic action of different extracellular and intracellular enzymes produced by the mixed dominant PVA-degrading bacterial strains. In this process, PVA was first degraded into ketones, fatty acids and alcohols. It was then regenerated into acetic acid, hydrogen and carbon dioxide. Finally, these substances could be further utilized by methanogens. PVA was thus degraded completely. This study may serve as a reference for future works on the degradation of PVA in the ecological environment. It may also guide the sustainable development of PVA.