Β-glucosidase Enzyme Activity Research Articles

Native broad-leaved tree species play key roles on maintaining soil chemical and microbial properties in a temperate secondary forest, Northeast China

Silviculture of appropriate tree species can improve soil properties, subsequently ameliorating the productivity and ecological functions. However, it is not clear about the differences in the effects of tree species on soil properties in secondary forest ecosystems. In this study, four stands of 60–70 years secondary forests were chosen. Eight replicate individuals of five common native tree species: Acer mono, Quercus mongolica, Juglans mandschurica, Fraxinus rhynchophylla, and Fraxinus mandschurica were selected in each stand to test the effects of tree species on soil properties in a typical temperate secondary forest ecosystem in Northeast China. Forest floor, soil at three depths (0–10, 10–20 and 20–40 cm) were compared among five tree species. Our findings showed significant differences in soil mineral nitrogen (N) (i.e. NH4+-N and NO3–-N) and available phosphorus (P), microbial biomass C (MBC), microbial biomass N (MBN) and enzyme activities depending on the tree species. At 0–10 cm soil depth, F. mandschurica soils exhibited 18–28% higher mineral N than those A. mono, F. rhynchophylla, and Q. mongolica, 24–38% higher available P than Q. mongolica and F. rhynchophylla. Similarly, F. mandschurica soils showed 64–66% higher MBC and MBN than Q. mongolica, and 41–133% higher β-glucosidase enzyme activity than J. mandshurica, F. rhynchophylla, and Q. mongolica. At 10–20 cm soil depth, F. mandschurica exhibited higher soil mineral N and available P concentrations, MBC, enzyme activities of phenol oxidase, exoglucanase, and β-glucosidase than the other tree species. At 20–40 cm soil depth, there were no difference in soil mineral N and available P, MBC, MBN, and enzyme activities among five tree species. No differences were observed between the tree species in the C, N, and C/N ratio of forest floor; however, the C/N ratio of fine roots was lower for F. mandschurica than for Q. mongolica. Significant correlations were established between C/N ratio of fine roots and soil mineral N and available P, MBC and MBN, and phenol oxidase. This suggests that the high quality of F. mandschurica fine roots improved soil chemical and microbial properties. Nevertheless, these native tree species exhibited improving soil chemical and microbial properties, compared to larch plantation soils in secondary forest ecosystems. Therefore, we suggest that introduction of F. mandschurica followed by that of A. mono and J. mandshurica, and then Q. mongolica and F. rhynchophylla into larch plantations should be considered for restoring the degraded soils in plantations.

Microbiological indicators of soil quality are related to greater coffee yield in the Brazilian Cerrado region

Abstract One of the main challenges faced by the rapidly growing human population is to increase agricultural sustainability. Soil quality is an essential aspect of agricultural sustainability, but farmers have generally assessed this based on conventional chemical and physical indicators, with little application of indicators of soil functions, such as soil microbiological attributes. These indicators may respond faster to changes in soil conditions and thus they could correlate better with the growth/yield of crops such as coffee. The aim of this study was to investigate the potential of soil microbiological indicators in assessment of soil quality for sustained coffee production, compared to or combined with conventional soil physical and chemical indicators. To accomplish that, two observational studies were performed by measuring soil microbiological, physical, and chemical attributes in coffee field areas with contrasting records of coffee yield but under similar edaphic and climatic conditions in the Cerrado (Brazilian tropical savanna) region of Minas Gerais, Brazil. In the first study, two neighboring field areas with contrasting yield were selected for each of the following three cultivars: Catuai Vermelho IAC 99, Catuai Vermelho IAC 144, and Rubi MG 1192. Samples were taken in two seasons (dry and rainy) of the year. In the second study, four neighboring field areas cropped with the cultivar Catuai Vermelho IAC 144 were chosen based on their contrasting yield records. In both studies, the experimental procedure consisted of collecting four composite soil samples (each composed of four subsamples) taken at a depth of 0–10 cm from each field area within the area of canopy projection of the coffee plant. The microbiological attributes evaluated were microbial biomass carbon; microbial basal respiration; metabolic quotient; urease, β-glucosidase, and arylsulfatase enzyme activities; and fluorescein diacetate hydrolysis. The physical and chemical attributes evaluated were texture, pH, organic matter content, and fertility. Climatic conditions affected the responses and must be considered in evaluation and elaboration of soil quality indexes. The physical and chemical attributes that were most closely related to higher coffee yields were Ca contents, organic matter content, effective cation exchange capacity, and base saturation in both studies in the rainy season. Microbial biomass carbon, metabolic quotient, and β-glucosidase and urease activities were positively related to higher coffee yields, and these attributes exhibited greater ability to discriminate the production potential of the soil than chemical and physical attributes did, in both seasons and studies.

Changes in the soil due to the use of sheep in cover crop management in organic olive groves

This work studied the effects of cover crop management by livestock on soil properties, comparing it with other managements and uses of soil. For this, two olive-orchards were selected, one an ecological olive-orchard, surrounded by patches of natural vegetation and another under conventional management, both located in Pegalajar (Jaén, Spain). The study area was divided into 7 plots with four management types and three uses: two of the plots were not cultivated, one was lucerne (ESP) and the other one holm oak (ENC); one plot was under conventional management, with bare soil due to the application of herbicides (BL); one plot was managed by mechanical clearing (CON); three plots had a cover crop that was managed in the following ways: two plots with only sheep, for 2 years (G) and six years (GA) and the third plot with a combined management of livestock and mechanical clearing (Mix). The constituents and properties studied were: texture, bulk density, humidity, pH, exchangeable bases and cation exchange capacity (CIC), nitrogen (N), oxidizable organic carbon (CO), soluble organic carbon (COS), assimilable phosphorus (P), enzymatic activities β-glucosidase and dehydrogenase. The organic carbon content was the constituent that most affected the other parameters. As expected, the soils under holm oak, followed by lucerne, showed the highest concentrations of total organic carbon and soluble organic carbon and nitrogen. However, the concentration of total carbon in soils with livestock management was equal to that of the lucerne. The sequences from highest to lowest concentration were ENC > GA, ESP, G > BL for total carbon, and ENC, ESP > CON, G, GA, MIX > Bl for soluble carbon and nitrogen. In general bulk density and pH were lower in the uses and managements with higher CO content. On the contrary, the parameters of humidity, bases and cation exchange capacity were higher when the CO was also higher, although not always with significant differences. The β-Glucosidase activity was lower in holm oak, probably because the organic matter has a lower cellulose content. Finally, the dehydrogenase activity was significantly higher in holm oak and lucerne, which have continuous contributions of organic matter that favour a continual microbial activity, contrary to the rest of treatments that are more time-specific.

Enzyme Activity, Glomalin, and Soil Organic Carbon in Agroforestry Systems

Abstract This study aimed to evaluate enzyme activity, glomalin-related soil proteins (GRSP), soil chemical attributes, and total organic carbon (TOC) in two Agroforestry systems (AFS) (AFS-1 and AFS-2), in a traditional agriculture area (TA), and secondary forest (SF) area in Paraty (RJ). Soil samples (from 0 to 5 cm depth) were collected during the rainy and dry seasons. AFS improves and/or maintains soil chemical indicators based on pH increase, reduces aluminum saturation and maintains soil nutrient content (Ca, Mg and K), when compared with SF. The contribution of organic material and the biodiversity of the AFS provide the maintenance of the total organic carbon content of the soil. AFS maintain the activity of the enzymes protease, β-glucosidase, acid phosphatase, and total enzyme activity (FDA), and the production of glomalin-related soil protein at levels similar to those observed in SF, especially during the rainy season.

Clinical and Genetic Varieties of Gaucher Disease in Iraqi Children

AbstractGaucher disease (GD), which is due to a deficiency in the lysosomal enzyme β-glucocerebrosidase, is a rare genetic disorder. It is characterized by a wide variety of clinical manifestations and severity of symptoms, making it difficult to manage. A cross-sectional hospital-based genetic study was undertaken with 32 pediatric patients. We recruited 21 males and 11 females diagnosed with GD, with a male-to-female ratio of 1.91:1. The mean age of the study population was 8.79 ± 4.37 years with an age range from 8 months to 17 years. We included patients on clinical evaluation from 2011 to 2019. An enzyme assay test was used to measure β-glucosidase enzyme activity in leukocytes and the GBA gene study was performed by polymerase chain reaction technique. We found GD type 1 in 27 (84.37%) participants, GD type 3 in five (15.63%) participants, while none classified as GD type 2. The dominant mutation in GD 1 was N370S in 81.5%, of which two-thirds were homozygous. The second common mutation in this type of disease (L444P) was present in nine cases (40.9%), two of whom were homozygous (9.9%). Meanwhile, R463C was present in six cases (27.27%), of whom one was homozygous. In GD 3, the dominant mutation was L444P as seen in 80% of the patients followed by N370S and R463C in 20%. This study shows that the most common mutant allele in this study was N370S, followed by L444P. Further large-scale studies with more advanced designs are recommended to explore the sequences of GBA genes.

Preliminary Results of a Prospective Observational Study to Assess the Prevalence of Gaucher Disease in an Adult Population Affected By MGUS

INTRODUCTION: Gaucher disease (GD) is a rare, autosomal recessive genetic disorder. It is due to a deficiency of the lysosomal enzyme, glucocerebrosidase, which leads to an accumulation of its substrate, glucosylceramide, in tissue macrophage with damage to hematological, visceral, and skeletal organ systems. Although GD has a continuous spectrum of severity, it is traditionally classified into three forms: type 1 (chronic; lacking early onset neuronopathy), type 2 (acute; with early onset neuronopathy),and type 3 (chronic; with early onsetneuronopathy). Type 1GD accounts for more than 90% all GD patients. Its prevalence world-wide is 1 in 50,000-100,000 but it is as high as ~1 in 850 in individuals of Ashkenazi heritage. Type 1 GD is frequently associated to monoclonal gammopathies; despite the emergence of theories advanced to explain these observations, the cause remains unknown. OBJECTIVE: Aim of the ongoing observational study is to determine the prevalence of unrecognized type I GD in a selected Italian population with MGUS. MATERIALS AND METHODS: From January 2018, dried blood spots (DBS) sample from patients with laboratory evidence of MGUS coming from five hematology units of Sicily and Calabria were collected and tested for the acid β-glucosidase enzyme activity. The study was approved by the local institutional review board. All patients provided informed consent for the prospective collection of their data. In case of DBS positive result, a confirmatory test was carried over and, if GD was confirmed, the patient was referred to one of the Regional Reference Centers for Metabolic Disease, as for current clinical practice in Italy. RESULTS: To date, 308 patients with MGUS were enrolled; acid β-glucosidase enzyme activity was low in 22 patients (7%). Sequence analysis of GBA gene was performed in these selected patients, but we have found only 4 patients with heterozygous mutation in the GBA1 gene, 1 homozygous(c.1226A>G -N370S) and 1 compound heterozygous (c.1226A>G -N370S and c.1448T>C -L444P); the last 2 patients had signs of GD (hepato-splenomegaly and mild thrombocytopenia). CONCLUSIONS: Type 1 GD remains a rare lysosomal storage disorder but preliminary results of our observational study show that it should be considered in the diagnostic framework of patients with MGUS, particularly when other GD symptoms are present. Disclosures Conticello: Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding. Di Raimondo:Celgene: Consultancy, Honoraria, Research Funding; Takeda: Consultancy; Amgen: Consultancy, Honoraria, Research Funding.

Co-incorporation of green manure and rice straw improves rice production, soil chemical, biochemical and microbiological properties in a typical paddy field in southern China

The cultivation of green manure or rice straw returns in southern China increases crop yields and soil fertility. Few studies have reported the effects of combining both management techniques on rice performance and soil fertility. A 3-year field study was carried out to analyse the impacts of the co-incorporation practice on soil microbial and biochemical parameters as well as crop yield. Five treatments were tested: (i) no-fertilizer (CK); (ii) chemical fertilizer (F); (iii) F plus green manure (FM); (iv) F plus rice straw (FS); (v) F plus green manure plus rice straw (FMS). The results showed that incorporation of green manure and/or rice straw increased double rice yields by 4.1% (FM), 4.7% (FS) and 9.6% (FMS) compared with F. The FMS treatment enhanced soil organic C (SOC), total N (TN), mineral N (Nmin), and available K (AK) levels by combining the advantage of FM in increasing TN and Nmin and the advantage of FS in increasing SOC and AK in comparison with F. The incorporation of green manure and/or rice straw stimulated microbial growth (total phospholipid fatty acids, PLFAs) and altered the soil microbial community structure relative to F, in which FMS had the greatest effect. The enzyme activities of β-glucosidase, β-cellobiosidase, N-acetyl-glucosaminidase, L-leucine aminopeptidase and phosphatase were higher in the green manure and/or rice straw application treatments than in the F treatment in the order FM ≈ FS < FMS. The partial least squares path model (PLS-PM) analysis indicated that green manure mainly influenced the abovementioned indices in the early rice season, while the effects of rice straw lasted until the late rice season. Our results suggest that co-incorporation of green manure and rice straw is a more effective practice for improving soil fertility and rice yields.

Temporal Impacts of Different Fertilization Systems on Soil Health under Arid Conditions of Potato Monocropping

The aim of this study was to determine temporary impacts of different fertilization systems on some labile soil biochemical and biological properties following potato monocropping under arid conditions. Field and incubation experiments were conducted to determine specifically soil organic carbon (SOC); dissolved organic carbon (DOC); dissolved organic nitrogen (DON); microbial biomass C (Cmic), N (Nmic), P (Pmic); bacterial and fungi counts; soil resistance index (SRI); net N mineralization (Nmin); and some enzyme activity. Levels of SOC; DOC; Nmin, Cmic, Pmic; bacteria and fungi counts; and soil respiration (SR) were significantly increased under organic and integrated fertilization systems compared with inorganic nano or NPK fertilization system, while levels of microbial biomass N (Nmic) and DON were markedly increased under nano or fertilizers compared to organic or integrated (organic + inorganic) fertilizers. By contrast, higher values of metabolic quotient (qCO2) were recorded in nano or fertilizer treatments suggesting that microbial biomass was less efficient under high maintenance of soil carbon. Enzyme activities of dehydrogenase (DH), β-glucosidase (βG), and acid phosphatase (Ac-P) were in the order of organic > integrated > inorganic fertilization systems, while enzyme activity of urease (UR) was in the vice versa order. Integrated fertilization system recorded greater levels of SOC; DOC; Nmin, Cmic, Pmic; and SR relative to inorganic fertilizers even though applied at lower rates. It is, therefore, important for soils under monocropping system to poise organic and inorganic fertilization system that enhances soil health and soil organic matter build-up.

Acute effects of nanoplastics and microplastics on periphytic biofilms depending on particle size, concentration and surface modification

Microplastics (MPs) can disintegrate into smaller sized microplastics and even nanoplastics (NPs). The toxicity of nanoplastics and microplastics on freshwater organisms have been well explored recently, however, very little is known about the potential impacts of NPs on freshwater biofilms, which are essential for primary production and nutrient cycling in aquatic ecosystems. In this study, we studied the acute effects (3 h of exposure) of polystyrene beads (PS, with diameter range from 100 nm to 9 μm) on five biological endpoints targeting community and ecosystem-level processes in biofilms: chlorophyll a, photosynthetic yield, and three extracellular enzyme activities. The results showed that the large size PS beads (500 nm, 1 μm, and 9 μm) exhibited negligible effects on the determined biological endpoints in biofilms within the range of concentrations (5–100 mg/L) in this study. However, high concentration of PS beads (100 nm, 100 mg/L) significantly decreased the content of chlorophyll a, and the functional enzyme activities of β-glucosidase and leucine aminopeptidase, suggesting negative effects on the carbon and nitrogen cycling of freshwater biofilms. Moreover, the influences of PS NPs (100 nm) on biofilms strongly depended on the surface modification of PS particles, with the positively charged PS NPs (amide-modified) exhibiting the highest toxicity to biofilms. The excess generation of reactive oxygen species (ROS) in this study indicated oxidative stress induced by PS NPs, which might lead to the observed nano-toxic effects on biofilms. In response, the antioxidant activity of biofilm was enhanced as indicated by the increased total antioxidant capacity (T-AOC). Overall, our findings highlight nanoplastics have potential to disrupt the basic ecological functions of biofilms in aquatic environments.

Effects of Amendments with Different C/N/P Ratios on Plant and Soil Properties of a Pb-Zn Mine Tailings

A field trial was conducted with abandoned Pb-Zn mine tailings to evaluate the effectiveness of amendments with different C/N/P ratios on plant growth, soil nutrients and enzyme activities, and heavy metal concentrations in plant tissues and the mine tailings. The following results were noted. ①The application of amendments with different C/N/P ratios promoted plant growth and development. The vegetation cover and biomass increased from 2.0%-20.0% and 9.4-115 g·m-2 at 6 months to 62.5%-98.5% and 389-2358.3 g·m-2 at 30 months, respectively. ②When compared with the control tailings, the mean values of organic carbon, water organic carbon, nitrate nitrogen, and available phosphorus in the treatments with different C/N/P ratios increased 6.0%-93.3%, 1.3%-49.3%, 12.3%-214.7%, and 2.7%-81.3%, respectively. Similarly, the addition of amendments with different C/N/P ratios enhanced the soil enzyme activities of dehydrogenase, β-glucosidase, urease, and phosphatase 0.3-2.8, 0.1-1.4, 0.1-0.6, and 0.1-0.5 times those in the tailings. ③The addition of amendments with different C/N/P ratios decreased the concentrations of diethylenetriamine pentaacetate (DTPA)-extracted Cd, Cu, Pb, and Zn in the mine tailings and the accumulation of Cd, Cu, Pb, and Zn in plant tissues in different degrees. DTPA-Cd, DTPA-Cu, DTPA-Pb, and DTPA-Zn decreased 2.5%-40.2%, 1.4%-25.6%, 1.4%-15.2%, and 0.4%-24.9%, respectively, compared with the control tailings. ④Pearson's correlation coefficients showed that the vegetation cover and biomass were correlated positively with the soil nutrient elements and enzyme activities and negatively with DTPA-extractable metal concentrations. No correlations were observed between the plant metal concentrations and soil DTPA-extractable metal concentrations, nutrient elements, and enzyme activities. Generally, amendments with different C/N/P ratios aided phytostabilization of some types of mine tailings is the preferred option for full remediation of these mine wastelands.

Stability characteristics of soil organic carbon pool following development of sand-fixing forest in Mu Us sandy land, China

The study aimed to reveal the cumulative effects and stability characteristics of soil organic carbon (SOC) during forest development at the Mu Us sandy land, China. Using space for time substitution, surface soil samples were collected from semi-fixed sandy lands and restored arbor and shrub lands with the ages of 22, 32 and 53 years in the Yulin sand control region in Northern Shaanxi Province. The content of total organic carbon (TOC), oxidizable labile organic carbon, and resistant carbon and the characteristics of mineralized carbon emission and decomposition ratio were analyzed. The results showed that the increment of TOC for 22 to 53 years shrub and arbor lands from resistant carbon were 3.5-6.2 g·kg-1 and 3.2-7.7 g·kg-1, and from oxidized labile carbon were 2.8-3.4 g·kg-1 and 1.3-2.8 g·kg-1, respectively, compared with semi-fixed sand land. The ratio of soil oxidizable labile carbon in shrub land and arbor land were stable and maintained at 37.0% and 26.8%, respectively. However, the ratio decreased to 25.7% and 17.4% after incubated at a constant temperature for 60 days. The mineralization rate of shrub and arbor lands with 22-53 years was not significant at the ending of soil incubation. Carbon losses from oxidized liable carbon were 76.9%-98.7%, and only 1.3%-23.5% from resistant carbon in all sand-fixing forest plots. Compared with the maximum carbon emission rate, the soil cumulative carbon release exhibited a higher correlation with soil enzyme activities of β-glucosidase and dehydrogenase, but the enzyme activities did not change from 32-53 years. In conclusion, SOC pool showed stable characteristics of lower emission and higher sequestration with the increases of sand-fixing forest stand age. The carbon fixation effect of arbor sand-fixing forest was better than that of shrub sand-fixing forest.

Effects of humic acid-modified magnetic Fe3O4/MgAl-layered double hydroxide on the plant growth, soil enzyme activity, and metal availability

The synthesis of a humic acid-layered double hydroxide (HA-LDH) hybrid was purposed for the remediation of contaminated soils in mining area. The hybrid was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscope and energy dispersive spectrometer. In order to investigate the effect of HA-LDH on the mine soil, greenhouse experiments of Artemisia ordosica were carried out under different concentrations of amendments (0, 1%, 3%, 5%, 7%). The plant growth, metal availability, and soil enzyme activities were studied to determine the effects of HA-LDH. The mine soil with 5% HA-LDH was the optimum proportion, and the growth of Artemisia ordosica was in good status. The HA-LDH and Artemisia ordosica could effectively decrease the bioavailability of heavy metals (such as Pb, Cr, Ni, Cd, Zn, and As) in the mine soil, and improve the enzyme activities of β-glucosidase, urease, and phosphatase. The HA-LDH with magnetism could be easily separated. The characteristics and reusability of HA-LDH could be well maintained after five cycles of remediation. Consequently, the HA-LDH is promising for the remediation of contaminated soils in mining area.

Developing Efficient Thermophilic Cellulose Degrading Consortium for Glucose Production From Different Agro-Residues

In the present study, eleven cellulose degrading bacterial strains were isolated from water and soil samples of hot springs in the Chumathang village, Leh and Ladakh region, India. The isolated strains were identified as Bacillus subtilis, Bacillus aryabhattai, Bacillus stratosphericus, Bacillus altitudinis and Brevibacterium frigoritolerans by biochemical and molecular approaches. All the strains were evaluated for the total cellulase, endoglucanase, exoglucanase, and β-glucosidase enzyme activities. On the basis of overall individual cellulose degrading enzyme activities, three strains were selected to develop consortium to enhance their cellulase enzyme activities. The potent cellulose degraders B. stratosphericus BHUJPV-H5, B. subtilis BHUJPV-H19 and B. subtilis BHUJPV-H12 were selected for the consortium development. The effect of cellulase activities of bacterial strains were evaluated ranged up to 6.06 and 0.72 mg ml-1glucose by agro-residues of sugarcane bagasse and wheat straw, respectively after 1 h of incubation. Total cellulase enzyme activity of consortium was recorded two times higher than the individual organisms. These strains can be used for enhancing bioethanol production from lignocellulosic biomass, which can consequently boost biofuel production industry.

Construction of novel Trichoderma orientalis EU7-22, strain with improved β-glucosidase activity by cellobiohydrolase I promotor optimization from Trichoderma reesei

Abstract An upstream region of cellobiohydrolase I gene promoter was modified from Trichoderma reesei to enhance heterologous gene expression. The base pairs from −677 to −724 were deleted indicating glucose repressor binding sites. Trichoderma reesei is considered an important workplace for homologous/heterologous genes expressions under the modified cbh1 promoter. However, constitutive expression is desirable in some cases over inducible expression that leads to production of undesirable cellulase components as byproduct. Here we report that the reporter β-glucosidase gene (bgl1) from Aspergillus niger BE-2 was cloned and recombined with cbh1 promoter followed by terminator trpC cloned from fungal expression vector, pUR5750. The expression cassette was ligated to binary vector and transferred into the host strain EU7-22 via Agrobacterium tumefaciens mediated transformation (ATMT) using hygromycin B resistance gene as the screening marker. Four transformants Bgl-1, Bgl-2, Bgl-3 and Bgl-4 were screened. Compared with the host strain EU7-22, the enzyme activities of filter paper (FPA) and β-glucosidase (BG) of transformant Bgl-3 increased by 39% and 47.1% under repression condition respectively. The expression level of Bgl-3 was found 7.9 folds increase over host strain EU7-22. Our results indicate that cbh1 is a strong promoter and has successfully driven over-expression of bgl1 gene in EU7-22 under repression condition and has surprisingly improved the efficiency of heterologous expression of cellulase genes in EU7-22.

Reduced catalytic activity of an exogenous extracellular β-D-glucosidase due to adsorption on a model humic-clay complex and different soils under wetting and drying cycles

To ascertain the role of extracellular enzymes in soil biochemical reactions, we followed the changes in catalytic activity of an exogenous β-glucosidase (GLU) enzyme after its adsorption on a synthetic model humic-clay complex, composed by a lignite humic acid coupled by Al bridges to a Ca-montmorillonite (HM), and on three sterilised soils (DS, ISC and IST) with different properties. Either HM or the selected soils enabled a stable GLU adsorption that induced a significant decrease of GLU activity. In the case of soils, both the largest GLU adsorption and reduction of catalytic activity was observed for the clayey and organic matter-rich ISC soil. When the GLU-soil adducts were subjected to wetting and drying (W/D) cycles for 3 and 6 weeks, the enzyme activity was further largely reduced after the first 3 weeks of W/D, while the decrease progressed more slowly during the following 3 weeks. This was attributed to the increasing modification of the enzyme conformational structure due to formation of dispersive and hydrogen bonds with the inorganic and organic components of HM and soils. Our results showed that an exogenous extracellular enzyme, such as GLU, is quantitatively immobilised on model and real soil aggregates, and that the catalytic activity is significantly and progressively reduced by soil physical-chemical changes, thereby implying that soil biochemical transformations are to be accounted more to intracellular than extracellular enzymes.

Microbial lipids from cellulolytic oleaginous fungus Penicillium citrinum PKB20 as a potential feedstock for biodiesel production

Microbial lipids derived from oleaginous fungi are considered as an alternative feedstock for biodiesel production. We attempt to isolate a cellulolytic oleaginous fungi as a potential feedstock for biodiesel production. The fungus was identified by 5.8 S-ITS rRNA gene sequencing. The extracellular enzyme activities were recorded after every 24 h for 7 days. Nile red staining and fluorescence microscopy was used to visualise the lipid bodies within the fungal hyphae. A renewable heterogeneous base catalyst derived from Musa balbisiana cola peels was used for the transesterification of Penicillium citrinum PKB20 derived oil into biodiesel. GC-MS analysis was used to analyse the fatty acid methyl esters (FAME) profile of the transesterified lipids. Penicillium citrinum PKB20 was isolated from detritus rich soil of Assam, India. The endoglucanase, xylanase and β-glucosidase enzyme activities were found to be 292.83 ± 0.29, 111.72 ± 0.45 and 6.54 ± 0.13 U/mg respectively. The specific enzyme activity for extracellular lipase was found to be 3.12 ± 0.16 U/mg. It could accumulate up to 60.61% of lipids in nitrogen-limited medium (7.34 ± 0.45 g/L biomass production). The extracted lipids were converted to biodiesel with 89.3% conversion efficiency. The predominant fatty acids were oleic acid (30.09%), palmitic acid (20.25%) and linoleic acid (33.14%) suggesting a balance between oxidative stability and cold flow properties for suitable biodiesel quality. Penicillium citrinum PKB20 was found to be a potential feedstock for biodiesel production with desirable fuel properties. The cellulolytic nature could be utilised for simultaneous lipid production directly on cellulosic substrates.

Optimization of lactic acid fermentation conditions for fermented tofu whey beverage with high-isoflavone aglycones

Four lactic acid bacteria strains (Lactobacillus paracasei, Leuconostoc mesenteroides, Lactobacillus rhamnosus GG and Lactobacillus plantarum), possessing β-glucosidase enzyme activity, were investigated for tofu whey fermentation based on the capacity of bioconversion of isoflavones. The results suggested that the mixture of L. rhamnosus GG and L. paracasei had great potential for efficient enrichment of bioactive isoflavone aglycones and the percentage composition (daidzein, genistein) increased from 4.6 to 93.78% after fermentation of tofu whey. At the same time, the viable cell counts of the mixture of L. rhamnosus GG and L. paracasei increased to 9.13 log10 CFU/mL while pH value dropped to 4.48 and titratable acidity was 0.28%. Headspace solid-phase microextraction method followed by gas chromatography-mass spectrometry analysis indicated that the odor compounds, particularly the aldehydes and alcohols, were metabolized to trace or undetected levels after fermentation. This research provided not only a new way to develop a functional probiotic beverage enriched in isoflavone aglycones, but also provided a potentially valuable new use for soy whey protein.

Twenty-Five Years of Biochemical Diagnosis of Gaucher Disease: The Egyptian Experience

Background: Gaucher disease is a rare multi-systemic metabolic disorder resulting from the deficiency in β-glucocerebrosidase enzyme, with consequent accumulation of glucocerebroside. Less than 15% of mean normal activity β-glucocerebrosidase in leukocytes is the gold standard for the diagnosis of Gaucher disease, which is supplemented by a massive elevation in chitotriosidase enzyme activity. We report here our experience in the biochemical diagnosis of Gaucher disease by showing the variability and the heterogeneity of the activity of enzymes over 25 years from 1993-2017, through referring 5128 clinically suspected Gaucher disease cases to our Biochemical Genetics Department, National Research Centre, as the main reference lab in Egypt for the diagnosis of Inherited Metabolic Disorders. Methods: β-glucosidase enzyme activity and chitotriosidase were done to all referred cases. Sphinogmylinase activity was estimated for all cases with normal activity of β- glucosidase and moderate elevation of chitotriosidase. Results: Out of the 5128 suspected cases, 881 (17%) had deficiency in β-glucocerebrosidase activity, accompanied with high chitotriosidase activity level, ranges (213-66700 μmol/l/h) and mean (7254.8 μmol/l/h). Zero chitotriosidase activity is found in 9 patients (1%) with low β-glucosidase. 451 cases were diagnosed as Niemann Pick patients (8.8%). Discussion and Conclusion: Other biochemical markers are needed in addition to chitotriosidase enzyme for the diagnosis. Molecular testing was done in relatively small numbers and need to be available parallel with biochemical testing.

Soil Enzyme Activities and Their Relationship with Soil Physico-Chemical Properties and Oxide Minerals in Coastal Agroecosystem of Puducherry

The objectives of our research were to assess the soil enzyme activities in relation with soil physicochemical and oxide minerals in the coastal agroecosystem of Puducherry region, India. Soils from nine farms in organic (ORG), sustainable (SUS), and conventional (CON) farming were sampled. Organically managed farming system soils contain significantly higher amounts of soil total N, organic carbon, and a higher level of microbial biomass C and N. Urease, protease, β-glucosidase, cellulose, saccharase, xylanase, and alkaline phosphatase enzyme activities were higher in organic farming system soils compared to sustainable and conventional farming soils. In addition, silt, clay, Al2O3, CaO, Fe2O3, K2O, MgO, MnO, Na2O, and P2O5 oxides were higher in organic farming soil and they showed a significant positive correlation with soil enzyme activities. Our study revealed that soil enzyme activities and soil minerals were significantly affected by farm management practices. The organic farming system had improved the soil health, enzyme activities, and plant available nutrients in coastal agro-ecosystem.

A novel method for the highly efficient biotransformation of genistein from genistin using a high-speed counter-current chromatography bioreactor.

Genistein, an important soybean isoflavone compound, has gained attention for its significant properties. Compared with the glycone form of genistin, low content of genistein limits the use in food and pharmaceutical fields. In this study, a novel bioreactor with high-speed counter-current chromatography (HSCCC) was built for the highly efficient biotransformation of genistein from genistin. The solvent system for the bioreactor was selected according to the KD values. The selected solvent system was evaluated by the enzyme activity of β-glucosidase. An ethyl acetate/buffer solution was selected as the preferred solvent system for the HSCCC bioreactor. Optimum reactor parameters were selected according to the retention of the stationary phase. The HSCCC bioreactor was operated using different flow rates, and 2.0 mL min−1 was chosen as the optimal flow rate with a conversion rate of over 90% within 24 h; the novel bioreactor easily immobilized and recycled the enzyme and could be applied in the preparation of genistein.