Addition of aluminum oxide microparticles to Trichoderma viride My preculture enhances cellulase production and influences fungal morphology

Morphological engineering techniques have recently become popular, since they are used to increase the production of a variety of metabolites and enzymes when fungi are grown in submerged cultures. This study aimed to facilitate cellulase production by adding aluminum oxide to Trichoderma viride My precultures.

The results showed that the highest cellulase activity was achieved when aluminum oxide at 10 g/L was used, and the activities of cellulase for filter paper and endoglucanase activity assays increased from 519.11 to 607.35 U/mL by 17.1%, and from 810.08 U/mL to 917.59 U/mL by 13.3%, compared with the control, respectively. Addition of aluminum oxide decreased the size of T. viride My pellets and increased the final pH. The changes in pellet diameter after the addition of different concentrations of aluminum oxide were fitted using a modified exponential decay model, which could precisely predict the pellet size by controlling aluminum oxide concentration.

The optimum concentration of microparticles, and therefore pellet size, could significantly improve cellulase production, which is an encouraging step towards commercial cellulase production.

     

The survey on cellular and tissue-engineered therapies in Europe and neighboring Eurasian countries in 2014 and 2015

Background aims

With the support of five established scientific organizations, this report, the seventh of its kind, describes activity in Europe for the years 2014 and 2015 in the area of cellular and tissue-engineered therapies, excluding hematopoietic stem cell (HSC) treatments for the reconstitution of hematopoiesis.

Completely serum-free and chemically defined adipocyte development and maintenance

Background aims

In vitro engineered adipose tissue is in great demand to treat lost or damaged soft tissue or to screen for new drugs, among other applications. However, today most attempts depend on the use of animal-derived sera. To pave the way for the application of adipose tissue–engineered products in clinical trials or as reliable and robust in vitro test systems, sera should be completely excluded from the production process. In this study, we aimed to develop an in vitro adipose tissue model in the absence of sera and maintain its function long-term.

Agronomic and chemical performance of field‐grown tobacco engineered for triterpene and methylated triterpene metabolism

Squalene is a linear intermediate to nearly all classes of triterpenes and sterols and is itself highly valued for its use in wide range of industrial applications. Another unique linear triterpene is botryococcene and its methylated derivatives generated by the alga Botryococcus braunii race B, which are progenitors to fossil fuel deposits. Production of these linear triterpenes was previously engineered into transgenic tobacco by introducing the key steps of triterpene metabolism into the particular subcellular compartments. In this study, the agronomic characteristics (height, biomass accumulation, leaf area), the photosynthetic capacity (photosynthesis rate, conductance, internal CO₂ levels) and triterpene content of select lines grown under field conditions were evaluated for three consecutive growing seasons. We observed that transgenic lines targeting enzymes to the chloroplasts accumulated 50–150 times more squalene than the lines targeting the enzymes to the cytoplasm, without compromising growth or photosynthesis. We also found that the transgenic lines directing botryococcene metabolism to the chloroplast accumulated 10‐ to 33‐fold greater levels than the lines where the same enzymes were targeted to in the cytoplasm. However, growth of these high botryococcene accumulators was highly compromised, yet their photosynthesis rates remained unaffected. In addition, in the transgenic lines targeting a triterpene methyltransferase (TMT) to the chloroplasts of high squalene accumulators, 55%–65% of total squalene was methylated, whereas in the lines expressing a TMT in the cytoplasm, only 6%–13% of squalene was methylated. The growth of these methylated triterpene‐accumulating lines was more compromised than that of nonmethylated squalene lines.     

Bioerosion in a changing world: a conceptual framework

Bioerosion, the breakdown of hard substrata by organisms, is a fundamental and widespread ecological process that can alter habitat structure, biodiversity and biogeochemical cycling. Bioerosion occurs in all biomes of the world from the ocean floor to arid deserts, and involves a wide diversity of taxa and mechanisms with varying ecological effects. Many abiotic and biotic factors affect bioerosion by acting on the bioeroder, substratum, or both. Bioerosion also has socio‐economic impacts when objects of economic or cultural value such as coastal defences or monuments are damaged. We present a unifying definition and advance a conceptual framework for (a) examining the effects of bioerosion on natural systems and human infrastructure and (b) identifying and predicting the impacts of anthropogenic factors (e.g. climate change, eutrophication) on bioerosion. Bioerosion is responding to anthropogenic changes in multiple, complex ways with significant and wide‐ranging effects across systems. Emerging data further underscore the importance of bioerosion, and need for mitigating its impacts, especially at the dynamic land–sea boundary. Generalised predictions remain challenging, due to context‐dependent effects and nonlinear relationships that are poorly resolved. An integrative and interdisciplinary approach is needed to understand how future changes will alter bioerosion dynamics across biomes and taxa.     

From grey to green: Efficacy of eco‐engineering solutions for nature‐based coastal defence

Climate change is increasing the threat of erosion and flooding along coastlines globally. Engineering solutions (e.g. seawalls and breakwaters) in response to protecting coastal communities and associated infrastructure are increasingly becoming economically and ecologically unsustainable. This has led to recommendations to create or restore natural habitats, such as sand dunes, saltmarsh, mangroves, seagrass and kelp beds, and coral and shellfish reefs, to provide coastal protection in place of (or to complement) artificial structures. Coastal managers are frequently faced with the problem of an eroding coastline, which requires a decision on what mitigation options are most appropriate to implement. A barrier to uptake of nature‐based coastal defence is stringent evaluation of the effectiveness in comparison to artificial protection structures. Here, we assess the current evidence for the efficacy of nature‐based vs. artificial coastal protection and discuss future research needs. Future projects should evaluate habitats created or restored for coastal defence for cost‐effectiveness in comparison to an artificial structure under the same environmental conditions. Cost‐benefit analyses should take into consideration all ecosystem services provided by nature‐based or artificial structures in addition to coastal protection. Interdisciplinary research among scientists, coastal managers and engineers is required to facilitate the experimental trials needed to test the value of these shoreline protection schemes, in order to support their use as alternatives to artificial structures. This research needs to happen now as our rapidly changing climate requires new and innovative solutions to reduce the vulnerability of coastal communities to an increasingly uncertain future.     

Engineering Camelina sativa (L.) Crantz for enhanced oil and seed yields by combining diacylglycerol acyltransferase1 and glycerol‐3‐phosphate dehydrogenase expression

Plant seed oil‐based liquid transportation fuels (i.e., biodiesel and green diesel) have tremendous potential as environmentally, economically and technologically feasible alternatives to petroleum‐derived fuels. Due to their nutritional and industrial importance, one of the major objectives is to increase the seed yield and oil production of oilseed crops via biotechnological approaches. Camelina sativa, an emerging oilseed crop, has been proposed as an ideal crop for biodiesel and bioproduct applications. Further increase in seed oil yield by increasing the flux of carbon from increased photosynthesis into triacylglycerol (TAG) synthesis will make this crop more profitable. To increase the oil yield, we engineered Camelina by co‐expressing the Arabidopsis thaliana (L.) Heynh. diacylglycerol acyltransferase1 (DGAT1) and a yeast cytosolic glycerol‐3‐phosphate dehydrogenase (GPD1) genes under the control of seed‐specific promoters. Plants co‐expressing DGAT1 and GPD1 exhibited up to 13% higher seed oil content and up to 52% increase in seed mass compared to wild‐type plants. Further, DGAT1‐ and GDP1‐co‐expressing lines showed significantly higher seed and oil yields on a dry weight basis than the wild‐type controls or plants expressing DGAT1 and GPD1 alone. The oil harvest index (g oil per g total dry matter) for DGTA1‐ and GPD1‐co‐expressing lines was almost twofold higher as compared to wild type and the lines expressing DGAT1 and GPD1 alone. Therefore, combining the overexpression of TAG biosynthetic genes, DGAT1 and GPD1, appears to be a positive strategy to achieve a synergistic effect on the flux through the TAG synthesis pathway, and thereby further increase the oil yield.     

Natural products as modulators of the nuclear receptors and metabolic sensors LXR,FXR and RXR

Nuclear receptors (NRs) represent attractive targets for the treatment of metabolic syndrome-related diseases. In addition, natural products are an interesting pool of potential ligands since they have been refined under evolutionary pressure to interact with proteins or other biological targets.This review aims to briefly summarize current basic knowledge regarding the liver X (LXR) and farnesoid X receptors (FXR) that form permissive heterodimers with retinoid X receptors (RXR). Natural product-based ligands for these receptors are summarized and the potential of LXR, FXR and RXR as targets in precision medicine is discussed.     

Recent advances in biological production of erythritol

Erythritol is a natural sweetener commonly used in the food and pharmaceutical industries. Produced by microorganisms as an osmoprotectant, it is an ideal sucrose substitute for diabetics or overweight persons due to its almost zero calorie content. Currently, erythritol is produced on an industrial scale through the fermentation of sugars by some yeasts, such as Moniliella sp. However, the popularity of erythritol as a sweetener is still small because of its high retail price. This creates an opportunity for further process improvement. Recent years have brought the rapid development of erythritol biosynthesis methods from the low-cost substrates, and a better understanding of the metabolic pathways leading to erythritol synthesis. The yeast Yarrowia lipolytica emerges as an organism effectively producing erythritol from pure or crude glycerol. Moreover, novel erythritol producing organisms and substrates may be taken into considerations due to metabolic engineering. This review focuses on the modification of erythritol production to use low-cost substrates and metabolic engineering of the microorganisms in order to improve yield and productivity.