Photoautotrophic and Mixotrophic Cultivation of Polyhydroxyalkanoate-Accumulating Microalgae Consortia Selected under Nitrogen and Phosphate Limitation

Microalgae consortia were photoautotrophically cultivated in sequencing batch photobioreactors (SBPRs) with an alteration of the normal growth and starvation (nutrient limitation) phases to select consortia capable of polyhydroxyalkanoate (PHA) accumulation. At the steady state of SBPR operation, the obtained microalgae consortia, selected under nitrogen and phosphate limitation, accumulated up to 11.38% and 10.24% of PHA in their biomass, which was identified as poly(3-hydroxybutyrate) (P3HB). Photoautotrophic and mixotrophic batch cultivation of the selected microalgae consortia was conducted to investigate the potential of biomass and PHA production. Sugar source supplementation enhanced the biomass and PHA production, with the highest PHA contents of 10.94 and 6.2%, and cumulative PHA productions of 100 and 130 mg/L, with this being achieved with sugarcane juice under nitrogen and phosphate limitation, respectively. The analysis of other macromolecules during batch cultivation indicated a high content of carbohydrates and lipids under nitrogen limitation, while higher protein contents were detected under phosphate limitation. These results recommended the selected microalgae consortia as potential tools for PHA and bioresource production. The mixed-culture non-sterile cultivation system developed in this study provides valuable information for large-scale microalgal PHA production process development following the biorefinery concept.

Mechanism That Allows Manno-Oligosaccharide To Promote Cellulose Degradation By Microbes And Composting of Cow Manure With Straw

New sugar source, manno-oligosaccharide, can regulate the structure of microbes. The effects of adding manno-oligosaccharide at four different levels (0, 0.1%, 0.5%, and 1% w/w compost) to cow manure–straw compost on the composting process, degradation of lignocellulose, and bacterial community in this study was investigated. The results showed that adding 0.5% manno-oligosaccharide had the greatest effects on accelerating the composting process, reducing the toxicity, and improving the stability of the product. After composting for 25 days, 0.5% oligosaccharide treatment can decrease the hemicellulose, cellulose, and lignin contents to 2.25%, 11.25%, and 7.07% respectively, compared with CK. Manno-oligosaccharide affected the distribution of the bacterial community, inhibited pathogenic bacteria, and improved the abundance of functional genes. Finally, adding 0.5% manno-oligosaccharide mainly affected the degradation of lignocellulose by enhancing the C/N value and the abundances of Streptomyces and the secretion system during composting was demonstrated by redundancy analysis.

Valorization of Greenhouse Horticulture Waste from a Biorefinery Perspective

Greenhouse cultivation and harvesting generate considerable amounts of organic waste, including vegetal waste from plants and discarded products. This study evaluated the residues derived from tomato cultivation practices in Almería (Spain) as sugar-rich raw materials for biorefineries. First, lignocellulose-based residues were subjected to an alkali-catalyzed extrusion process in a twin-screw extruder (100 °C and 6–12% (w/w) NaOH) to assess maximum sugar recovery during the subsequent enzymatic hydrolysis step. A high saccharification yield was reached when using an alkali concentration of 12% (w/w), releasing up to 81% of the initial glucan. Second, the discarded tomato residue was crushed and centrifuged to collect both the juice and the pulp fractions. The juice contained 39.4 g of sugars per 100 g of dry culled tomato, while the pulp yielded an extra 9.1 g of sugars per 100 g of dry culled tomato after an enzymatic hydrolysis process. The results presented herein show the potential of using horticulture waste as an attractive sugar source for biorefineries, including lignocellulose-based residues when effective fractionation processes, such as reactive extrusion technology, are available.

Gummy candies production with natural sugar source: Effect of molasses types and gelatin ratios

Nowadays, attention has been dedicated towards the development of foodstuffs whose constituents are from natural sources. In this study, grape, mulberry, and carob molasses containing natural sugars were evaluated in order to replace the use of sugar syrup and artificial additives in the production of gummy candy which was prepared by varied gelatin ratios. The molasses which have similar °Brix values (78–79) presented different types and amounts of sugar components. High invert sugar with low sucrose was observed in grape and mulberry but high sucrose with low fructose and glucose appeared in carob molasses. Unlike grape and mulberry, carob based jellies had a whitish appearance possibly as a result of the crystallization due to its high sucrose/invert sugar ratio. For all parameters of TPA, carob candy with 5 g/100 g gelatin and grape candy with 10 g/100g gelatin had the lowest and highest values, respectively. Gelatin concentration dependency trend of hardness, gumminess, chewiness and resilience was determined as grape > mulberry > carob. No significant effect ( p > 0.05) on gelling temperatures (21–29 °C) but significant effect (p < 0.05) on melting points (33–39 °C) of molasses types were observed for candies. The properties of grape based candy having higher thermal stability and lower temperature sensitivity were attributed to its higher total sugar contents than other samples. The sensorial acceptability score for molasses gummy candies obtained more than 3.0 on a 5-point hedonic scale. These results illustrate the potential for the use of molasses in a healthier confectionery product development instead of commonly used sugars.

The past determines the future: sugar source history and transcriptional memory

Transcriptional reinduction memory is a phenomenon whereby cells “remember” their transcriptional response to a previous stimulus such that subsequent encounters with the same stimulus can result in altered gene expression kinetics. Chromatin structure is thought to play a role in certain transcriptional memory mechanisms, leading to questions as to whether and how memory can be actively maintained and inherited to progeny through cell division. Here we summarize efforts towards dissecting chromatin-based transcriptional memory inheritance of GAL genes in Saccharomyces cerevisiae. We focus on methods and analyses of GAL (as well as MAL and INO) memory in single cells and discuss the challenges in unraveling the underlying mechanisms in yeast and higher eukaryotes.

Study on Glycosylation Modification Technology of Semen Euphorbiae Meal Protein

In order to improve the solubility, emulsification and foamability of the Semen Euphorbiaee, and to improve the utilization of the Semen Euphorbiae, this experiment used glucose as a sugar source and modified the Semen Euphorbiae protein by wet glycosylation. Using solubility as a judgment index, a single factor test was conducted to optimize the conditions for the glycosylation reaction of the golden gold meal protein. The results showed that the solubility and other functional properties of the golden gold meal protein obtained by glycosylation under the conditions of pH 10.5, temperature 83.5 ° C, and meal protein / glucose mass ratio 1: 1.5 were improved.

The Effect of Different Sugars on Water Kefir Grains

Water kefir is a fermented probiotic beverage produced by fermentation of dried sugary fruits and sugar using water kefir grains. Sucrose is used as a sugar source in the traditional production of water kefir. The aim of this study is to determine the effects of grape molasses, honey and unrefined sugar on water kefir grains instead of sucrose. In the study, 4 groups were formed: grape molasses (10 g), honey (10 g), unrefined sugar (10 g) and refined sugar (10 g). 2 g of water kefir grain and 500 mL of drinking water were used for each group. And each group samples were fermented for 25°C 48 hours. The study continued for 5 weeks. The pH values and the titratable acidity values of water kefir samples and the weight of water kefir grains were determinated once every two day, while microbiological analyzes (Lactobacillus spp., Lactococcus spp. and yeast contents) and ethanol content of samples were determinate once every 15 days. In this study; it has been observed that the use of different sugars has no significant effect on the weights of the water kefir grains. In addition, it was determined that the Lactococcus spp. and yeast amounts in the water kefirs were higher in the samples produced by using honey and grape molasses. As a result, it was revealed that grape molasses, honey and unrefined sugar could be used as fermentation substrate in production of water kefir. At the same time, water kefir can be shown as an alternative fermented product for vegan consumers with allergies to dairy products.

The Roles of Different Sugar Sources on the Quality of Nigella Enriched Tomato Ketchup

The study was concerned to evaluate the effect of table sugar, honey and zero-calorie sugar on the quality of nigella enriched tomato ketchup. Ketchup was prepared by mixing 5, 10 and 15% nigella paste with tomato pulp. The variations in taste, color and texture were analyzed based on the consumers’ acceptability and 5% nigella paste was appropriate for product development. Three different types of sugar source (table sugar/honey/zero-calorie sugar) were used to prepare nigella enriched tomato ketchup. Moisture content and total soluble solids (TSS) were significantly lower in the sample S2 (tomato ketchup prepared with honey) which was 64.00±1.75% and 18.00±1.8%, respectively. Sample S1 (tomato ketchup prepared with table sugar) contained higher moisture content (65.40±1.55%); though it's not significantly different with sample S3 (tomato ketchup prepared with zero-calorie sugar). Sample S3 contained significantly (p<0.05) higher amount of TSS (25±1.6%) than other samples. In case of color analysis, it was observed that L*, a* and b* value reduced for all samples when treated with sodium benzoate but not significantly different. Sensory analysis suggested that sample S1 was suitable for the processing of nigella enriched tomato ketchup.