Pectinase production by <Emphasis Type="Italic">Aspergillus giganteus</Emphasis> in solid-state fermentation: optimization,scale-up,biochemical characterization and its application in olive-oil extraction

The application of pectinases in industrial olive-oil processes is restricted by its production cost. Consequently, new fungal strains able to produce higher pectinase titers are required. The aim of this work was to study the capability of Aspergillus giganteus NRRL10 to produce pectinolytic enzymes by SSF and evaluate the application of these in olive-oil extraction. A. giganteus was selected among 12 strains on the basis of high pectinolytic activity and stability. A mixture composed by wheat bran, orange, and lemon peels was selected as the best substrate for enzyme production. Statistical analyses of the experimental design indicated that pH, temperature, and CaCl₂ are the main factors that affect the production. Subsequently, different aeration flows were tested in a tray reactor; the highest activity was achieved at 20 L min^?1 per kilogram of dry substrate (kgds). Finally, the pectinolytic enzymes from A. giganteus improved the oil yield and rheological characteristics without affecting oil chemical properties.     

Strain engineering and process optimization for enhancing the production of a thermostable steryl glucosidase in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Biodiesels produced from transesterification of vegetable oils have a major problem in quality due to the presence of precipitates, which are mostly composed of steryl glucosides (SGs). We have recently described an enzymatic method for the efficient removal of SGs from biodiesel, based on the activity of a thermostable β-glycosidase from Thermococcus litoralis. In the present work, we describe the development of an Escherichia coli-based expression system and a high cell density fermentation process. Strain and process engineering include the assessment of different promoters to drive the expression of a codon-optimized gene, the co-expression of molecular chaperones and the development of a high cell density fermentation process. A 200-fold increase in the production titers was achieved, which directly impacts on the costs of the industrial process for treating biodiesel.     

Consolidated ethanol production from Jerusalem artichoke tubers at elevated temperature by <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> engineered with inulinase expression through cell surface display

Ethanol fermentation from Jerusalem artichoke tubers was performed at elevated temperatures by the consolidated bioprocessing strategy using Saccharomyces cerevisiae MK01 expressing inulinase through cell surface display. No significant difference was observed in yeast growth when temperature was controlled at 38 and 40 °C, respectively, but inulinase activity with yeast cells was substantially enhanced at 40 °C. As a result, enzymatic hydrolysis of inulin was facilitated and ethanol production was improved with 89.3 g/L ethanol produced within 72 h from 198.2 g/L total inulin sugars consumed. Similar results were also observed in ethanol production from Jerusalem artichoke tubers with 85.2 g/L ethanol produced within 72 h from 185.7 g/L total sugars consumed. On the other hand, capital investment on cooling facilities and energy consumption for running the facilities would be saved, since regular cooling water instead of chill water could be used to cool down the fermentation system.     

A genetic analysis of the quality of northern-style Chinese steamed bread

Dissecting the genetic basis for the traits of northern-style Chinese steamed bread (NCSB) is of great significance for wheat quality breeding. Quantitative trait loci (QTLs) for the processing quality of NCSB were studied using a recombinant inbred line (RIL) consisting of 173 lines derived from a “Shannong01–35 × Gaocheng9411” cross. Twenty-four putative additive QTLs were detected on chromosomes 1A, 1B, 1D, 3A, 3B, 4A, 4B, 5B, 6B, and 7B. Of these QTLs, QTex1A.1-27, QHei5B.5-488, and QGum4B.4-17 had the highest contribution and accounted for 9.33, 10.9, and 12.0% of the phenotypic variations, respectively. Several co-located QTLs with additive effects were detected on chromosomes 1A, 1D, 4B, and 5B. Two clusters (RFL_CONTIG2160_524-WSNP_CAP12_C2438_1180601 and EX_C101685_705-RAC875_C27536_611) for height, total score, and texture and for chewiness, gumminess, and hardness were detected on chromosomes 1A and 4B, respectively. Two QTLs for chewiness and hardness (QCh1D-4, QHa1D-4) with additive effects were detected; these alleles could be good targets for improving the processing quality of steamed bread from common wheat (Triticum aestivum L.). In addition, QTLs for wheat flour quality and the associated correlations with NCSB were simultaneously analyzed. Negative correlations were detected between chewiness and the wet/dry gluten content (WGC/DGC) or protein content. Two QTLs (QCh4B.4-17 and QPr4B.4-17) and three QTLs (QCh4B.4-13, QWG4B.4-13, and QDG4B.4-13) clustered in the same chromosomal region. The detected QTL clusters should be further investigated during wheat breeding and could be used by breeders to improve wheat quality and especially the processing quality of NCSB.     

Frequency of a natural truncated allele of <Emphasis Type="Italic">MdMLO19</Emphasis> in the germplasm of <Emphasis Type="Italic">Malus domestica</Emphasis>

Podosphaera leucotricha is the causal agent of powdery mildew (PM) in apple. To reduce the amount of fungicides required to control this pathogen, the development of resistant apple cultivars should become a priority. Resistance to PM was achieved in various crops by knocking out specific members of the MLO gene family that are responsible for PM susceptibility (S-genes). In apple, the knockdown of MdMLO19 resulted in PM resistance. However, since gene silencing technologies such as RNAi are perceived unfavorably in Europe, a different approach that exploits this type of resistance is needed. This work evaluates the presence of non-functional naturally occurring alleles of MdMLO19 in apple germplasm. The screening of the re-sequencing data of 63 apple individuals led to the identification of 627 single nucleotide polymorphisms (SNPs) in five MLO genes (MdMLO5, MdMLO7, MdMLO11, MdMLO18, and MdMLO19), 127 of which were located in exons. The T-1201 insertion of a single nucleotide in MdMLO19 caused the formation of an early stop codon, resulting in a truncated protein lacking 185 amino acids, including the calmodulin-binding domain. The presence of the insertion was evaluated in 115 individuals. It was heterozygous in 64 and homozygous in 25. Twelve of the 25 individuals carrying the insertion in homozygosity were susceptible to PM. After barley, pea, cucumber, and tomato, apple would be the fifth species for which a natural non-functional mlo allele has been found.     

Functional proteomic insights in B-cell chronic lymphocytic leukemia

Introduction: B cell chronic lymphocytic leukemia (B-CLL) is a hematological malignancy considered as the most common leukemia in the Western world. The understanding of B cell differentiation is crucial for the diagnosis, prognosis, and treatment of the disease.

Areas covered: In this review, B-cell ontogeny and its relation with the CLL development, in combination with the proteomic approaches which could provide a deep characterization of the disease through the characterization of the cellular signaling pathways involved in the pathological cells is described.

Expert commentary: Although conventional strategies (genome sequencing, morphology assays, and immunophenotyping by flow cytometry and/or immunochemistry) have allowed the establishment of the disease stage based on different parameters, it is still necessary to utilize novel approaches (e.g., proteomics) that have the potential to simultaneously analyze thousands of molecules to improve understanding of CLL.     

Osmotic stress decreases complexity underlying the electrophysiological dynamic in soybean

• Studies on plant electrophysiology are mostly focused on specific traits of single cells. Inspired by the complexity of the signalling network in plants, and by analogy with neurons in human brains, we sought evidence of high complexity in the electrical dynamics of plant signalling and a likely relationship with environmental cues.
• An EEG‐like standard protocol was adopted for high‐resolution measurements of the electrical signal in Glycine max seedlings. The signals were continuously recorded in the same plants before and after osmotic stimuli with a ?2 MPa mannitol solution. Non‐linear time series analyses methods were used as follows: auto‐correlation and cross‐correlation function, power spectra density function, and complexity of the time series estimated as Approximate Entropy (ApEn).
• Using Approximate Entropy analysis we found that the level of temporal complexity of the electrical signals was affected by the environmental conditions, decreasing when the plant was subjected to a low osmotic potential. Electrical spikes observed only after stimuli followed a power law distribution, which is indicative of scale invariance.
• Our results suggest that changes in complexity of the electrical signals could be associated with water stress conditions in plants. We hypothesised that the power law distribution of the spikes could be explained by a self‐organised critical state (SOC) after osmotic stress.

     

Secondary biochemical and morphological consequences in lysosomal storage diseases

More than 50 hereditary lysosomal storage disorders (LSDs) are currently described. Most of these disorders are due to a deficiency of certain hydrolases/glycosidases and subsequent accumulation of nonhydrolyzable carbohydrate-containing compounds in lysosomes. Such accumulation causing hypertrophy of the lysosomal compartment is a characteristic feature of affected cells in LSDs. The investigation of biochemical and cellular parameters is of particular interest for understanding “life” of lysosomes in the normal state and in LSDs. This review highlights the wide spectrum of biochemical and morphological changes during developing LSDs that are extremely critical for many metabolic processes inside the various cells and tissues of affected persons. The data presented will help establish new complex strategies for metabolic correction of LSDs.