Enzyme Activity Values Research Articles

Immobilization of Amano AK Lipase from Pseudomonas fluorescens on Novel Silk Microfiber using Oxone®: Parameter Optimization for Enzymatic Assays and use in Esterification of Residual Palm Oil

Background: Biodiesel has been shown to be effectively produced by immobilized enzymatic catalysts. The selection of support material is a prominent factor for obtaining an efficient lipase. Silk fibroin (SF) is a natural polymer produced by glands of some arthropods, especially by the Bombyx mor, attracting attention for immobilization of lipase. Objective: This paper presents a novel method to obtain silk microfibers (SMF) from Oxone® salt in water, used as support for Amano AK lipase from Pseudomonas fluorescens in biodiesel production from deodorization distillate of palm oil (DDPO). Method: The oxone® salt in the presence of Ca2+ ions acts as a mineralizing agent in the peptide bonds present in silk fibroin, altering some of its physical and chemical properties, such as zeta potential, crystallinity, micro-morphology, infrared spectroscopic profile, and showing formation or absence of SF original connections. Results: The modified support was tested as a support alternative for the immobilization of Amano AK lipase from Pseudomonas fluorescens. Enzyme activity values indicated that lipase immobilization on SMF was efficient as a heterogeneous catalyst in the esterification of DDPO (deodorization distillate palm oil). Conclusion: The effect of some reaction parameters, such as catalyst concentration, molar ratio, temperature, and reaction time, was studied to optimize the conditions for maximum conversion of DDPO (40.5%).

Important changes in germination, seedling tolerance, and active components content due to drought stress on three licorice (Glycyrrhiza) species

Drought stress triggers complex physiological and biochemical responses in plants. Different plant species have also evolved several morphological, physiological, biochemical, cellular, and molecular mechanisms to overcome drought stress conditions. However, genotype-specific response factors associated with drought tolerance and the balanced relationship between active components and stress conditions are still not fully elucidated. Licorice (Glycyrrhiza Tourn. L.) is a perennial herb of the Leguminosae family which is widely used as a spice in the food industry. It is favored for its sweet and distinctive aromatic flavor, which is attributed to its glycyrrhizic acid, liquiritin, and other components. The influence of drought stress on different species of licorice was analyzed. Seed germination parameters, the activity of anti-oxidative enzymes, osmoregulation, and active compound contents were compared in three licorice species (Glycyrrhiza glabra L., Glycyrrhiza uralensis Fisch., and Glycyrrhiza inflata Bat.). The results indicated a level of drought stress that balanced relatively good growth trends and high expression of active compounds in individual licorice species. With increasing drought stress, G. uralensis and G. glabra had lower values of early germination indicators (germination energy, germination rate, and germination index), when compared to G. inflata. The highest values of antioxidant enzyme activity and active compound content were detected at lower stress levels in both G. uralensis and G. glabra. The active components (glycyrrhizic acid, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, 4′,7-dihydroxyflavone, and licochalcone A) showed significantly different trends in different species under drought stress. The current study will help understand the effects of drought stress on licorice plants. The results highlight the importance of preserving regional genetic diversity for adaptive evolution in response to global climate change. It also provides a theoretical basis for revealing rational cropping regions and formulating adaptive irrigation strategies.

Enzyme Activity of Cellulolytic Bacteria from Biological Education and Research Forest Floor Andalas University

<b>Background and Objective:</b> The composition of the waste consists mostly of plant biomass. Cellulose is the largest component of plant biomass and cellulolytic bacteria are needed to degrade it. This study aimed to determine enzyme activity possessed by bacterial isolates from Biological Education and Research Forest floor Andalas University. <b>Materials and Methods:</b> The isolation stage was carried out with NA (Nutrient agar) medium, Screening with CMC (Carboxymethyl Cellulose) medium with congo red dye and enzyme activity testing was carried out using the Nelson-Somogyi method. <b>Results:</b> We found 16 bacterial isolates obtained from Biological Education and Research Forest Floor Andalas University, 10 of them were positive for cellulolytic bacteria with the highest cellulolytic index value of 2.59 on FFB 2 isolates. <b>Conclusion:</b> The bacterial isolate with the best enzyme activity value was FFB 2 isolate 0.166 U mL<sup>1</sup> for 72 hrs.

The Influence of Al3+ Metal Ion in AlCl3 Compound On α- Amylase Enzyme Activity

The influence of Al3+ metal ion in AlCl3 towards α-amylase enzyme activity have been studied. The activity of the α-amylase enzyme on potato starch substrate was determined using the DNS method (3,5-dinitrosalicylic acid) at optimum conditions. The data analysis was conducted in a descriptive qualitative manner. The results obtained that α-amylase enzyme activity with potato starch substrate was optimum at 20 mg/mL with pH 7.2, incubation temperature 37˚C, incubation time 15 minutes, and enzyme concentration of 40 mg/mL with an average enzyme activity value of 0.0079 mg/mL/minute at 37˚C. However, after the addition of Al3+ metal ion, the average value of enzyme activity decreased. These means that empirically Al3+ metal ion has a tendency to be inhibitory to the α-amylase enzyme activity on potato starch substrates.

Cellular Stress Pathways Are Linked to Acetamiprid-Induced Apoptosis in SH-SY5Y Neural Cells.

Simple SummaryNeonicotinoids constitute more than one-quarter of the insecticides on the market. Acetamiprid, a widely used neonicotinoid, has been found to be linked with neurological symptoms and there is an urge to understand its molecular mechanisms. It decreased cellular viability in millimole concentrations after 24 h in SH-SY5Y neural cells. Additionally, it increased reactive oxygen species, intracellular calcium and endoplasmic reticulum stress. Since overwhelmed cellular stress can destroy cellular structures and cause cell death, we also evaluated cellular death mechanisms. Acetamiprid induced apoptosis rather than necrosis indicating that cells undergo suicide initiated by self-generated death signals. Even though acetamiprid is considered to be a safe option in the struggle against harmful agricultural insects, these results suggest that the widespread use should be taken under strict control in order not to cause damage to the mammals.Acetamiprid (ACE), a commonly used neonicotinoid insecticide, is correlated with neurological symptoms, immunotoxicity and hepatotoxicity. Cellular stress and damage could play an important role in ACE-induced neurotoxicity; however, its mechanism has not been fully understood. We evaluated the effects of ACE on oxidative stress, endoplasmic reticulum (ER) stress, cellular death, mRNA expression levels of related genes and protein expressions of related molecular mechanisms in SH-SY5Y human neuroblastoma cells. The half maximal inhibition of enzyme activity (IC50) value of ACE was determined as 4.26 mM after 24 h of treatment by MTT assay. We revealed an increase in reactive oxygen species (ROS) production and calcium release. Significant increases were measured in inositol-requiring enzyme 1-alpha (IRE1-α) and binding immunoglobulin protein 90 (GRP90) levels as well as mRNA expression levels of caspase 3, 4 and 9 genes indicating enhanced ER stress. Apoptosis and ER stress-related genes were significantly upregulated at ≥2 mM. Indeed, ACE caused apoptosis and necroptosis while necrosis was not observed. There was a significant increase in the protein level of mitogen-activated protein kinase-8 (MAPK8) at 4 mM of ACE while no change was seen for nuclear factor kappa-B (NF-κB) and tumor necrosis factor-alpha (TNF-α). In conclusion, increased cellular stress markers could be proposed as an underlying mechanism of ACE-induced cell death in neural cells.

SlNAC6, A NAC transcription factor, is involved in drought stress response and reproductive process in tomato

Tomato plants are susceptible to drought stress, but the mechanism involved in this process still remains poorly understood. In the present study, we demonstrated that SlNAC6, a nuclear-localized protein induced by exogenous abscisic acid (ABA) or polyethylene glycol (PEG) stress treatment, plays a positive role in tomato plant response to PEG stress. Down-regulation of SlNAC6 (SlNAC6-RNAi) resulted in a semidwarf phenotype, and the SlNAC6-RNAi lines showed reduced tolerance to PEG stress, exhibiting a higher water loss rate and degree of oxidative damage, as well as lower values of proline content and antioxidant enzyme activity, when compared with those in wild type (WT). In contrast, overexpression of SlNAC6 (SlNAC6-OE) leads to a significant delay of growth, and the SlNAC6-OE lines showed greatly enhanced tolerance to PEG stress concomitant with a lower water loss rate and degree of oxidative damage, as well as higher values of proline content and antioxidant enzyme activity. Further study showed that the transcription level of ABA signaling-related genes and the ABA content are respectively decreased or increased in SlNAC6-RNAi and SlNAC6-OE seedlings, as verified by multiple physiological parameters, such as stomatal conductance, water loss rate, seed germination, and root length. Moreover, overexpression of SlNAC6 can accelerate tomato fruit ripening. Collectively, this study demonstrates SlNAC6 exerts important roles in tomato development, drought stress response, and fruit ripening processes, some of them perhaps partly through modulating an ABA-mediated pathway, which implies SlNAC6 may hold the potential applications in improving agronomic traits of tomato or other Solanaceae crops.

Ecology, biology and enzymatic activity of the rhizosphere planted with Larix decidua seedlings after addition of vermicompost

The aim of this study was to determine the influence of Eisenia fetida vermicompost (VC) added to forest nursery soil. The chemical reaction in the soil and selected microorganisms, such as bacteria, fungi and nematodes, were assessed. Larch seedlings were cultivated for 2 years in pots with nursery soil as a control and VC-amended soil in two doses: 10% (V10) and 20% (V20) v/v. One important observation was the connection between the addition of VC and the improvement of the plant's biometry and a much higher level of mycorrhization with increasing Suillus sp. Vermicompost modified the nematode community by reducing plant parasitic nematodes, and significantly increasing bacterial and fungivorous, as well as predatory nematodes. Actinomycetes bacteria, which were present in a proportion of 2.2% in the control soil, increased to 10.5% in V10, and to 5.4% in V20. Bacillus spp. increased along with the amount of VC from <0.01% in the control to 2.2% in V10 and to 2.7% in V20. The C:P ratio correlated negatively while the C:K ratio and N-NH4 concentration correlated positively with the abundance of Bacillus spp. Toxigenic Penicillium spp. and Fusarium spp. were suppressed. The stability of VC-amended soil system with respect to enzymatic activity was rather high, except for o-diphenol oxidase which was strongly reinforced by the VC. The enzyme activity values for all enzymes were correlated with an improvement in the values of the microbiological, biometric and nematode parameters and increased mycorrhization. One favorable modification, which was manifested in better seedling growth, was the effect of VC on the development of Suillus-morphotype mycorrhizal fungi, fungal feeder nematodes and Bacillus spp. Vermicompost may therefore be recommended in practice as a method of sustainable management for soil protection in larch forest nurseries.

A synthetic quality index to evaluate the functional stability of soil microbial communities after perturbations

Soil stability includes both resistance, the ability to withstand a perturbation or stress, and resilience, the ability to recover to pre perturbation levels. The functional stability of soil microbial communities is of paramount importance for the ecosystem functioning. We investigated the differences in the stability (resistance and resilience) of three enzyme activities (hydrolytic, laccase and peroxidase) in three different forest (holm oak, black pine and beech) soils after addition of PAHs (phenanthrene, pyrene and benzo[a]pyrene) with different molecular weights. Furthermore, we proposed a new soil quality index (MAI) based on the measured enzyme activity values, useful to quantify the ecological impact of soil perturbations (PAH exposure in our case).The degradation rates of different PAHs follow their complexity, slowing with increasing of PAH molecular weight in all soil types. Moreover, we found higher microbial resistance to PAH perturbation in “broad scale” enzyme activity (hydrolase), in respect to the two “narrow-niche” enzyme activities (laccase and peroxidase). The results demonstrate a higher functional stability in soils with a higher content of recalcitrant organic matter (soil under pine), compared to soils with higher content of labile organic matter (soil under holm oak). In particular, laccase activity is less affected by phenanthrene and pyrene addition in soil under pine; peroxidase activity shows a higher resistance and resilience in soil under beech for all PAHs added. Resistance and/or resilience to PAH contamination, observed for hydrolytic functional stability in the three soils, is mainly due to the high diversity of enzymes expressing this type of catalytic activity.

Nano Zinc Versus Bulk Zinc Form as Dietary Supplied: Effects on Growth, Intestinal Enzymes and Topography, and Hemato-biochemical and Oxidative Stress Biomarker in Nile Tilapia (Oreochromis niloticus Linnaeus, 1758).

Five isonitrogenous diets were formulated to comprise two forms of zinc (Zn): convention zinc oxide named Bulk-ZnO or zinc oxide nanoparticles (Nano-ZnO) supplemented at two levels 30 and 60 mg kg-1 compared to the control diet. Nile tilapia, Oreochromis niloticus, fingerlings (5.02-5.05 g) were fed tested diets two times a day for 84 days. The results displayed that the best growth and digestive enzyme activity (P < 0.05) were noticed in fish fed 60 mg kg-1 Nano-ZnO. Moreover, significant (P < 0.05) improvement in intestinal topography was observed in 60 mg kg-1 Nano-ZnO group versus other treatments. Furthermore, fish fed 30 mg kg-1 Nano-ZnO recorded the best values of hematological indices (P < 0.05). The alanine and aspartate aminotransferase (ALT and AST) values were lower, while total serum protein, albumin, and globulin contents were clearly higher in fish fed diet that contained 30 mg kg-1 Nano-ZnO versus other groups. The significant highest values of oxidative enzyme activity escorted with lower malondialdehyde value recorded of fish fed diet supplemented with 60 mg kg-1 Nano-ZnO.The results indicated that inclusion of Nano-ZnO at 60 mg kg-1 was the recommended source to enhance growth, feed utilization, amylase andlipase enzymes activity, intestinal morphology, hemato-biochemical, and oxidative response biomarkers of Nile tilapia compared with Bulk-ZnO incommercial tilapia feeds.

Thiol Disulfide Balance Oxidative Stress and Paraoxonase 1 Activities in Children and Adolescents Aged 6-16 Years with Specific Learning Disorders

Introduction: Specific learning disorders (SLD) are some of the most common neurodevelopmental disorders. The aim of this study is to determine the potential relationship between children with SLD and zinc, copper, paraoxonase 1 (PON1), arylesterase (ARY), ischemia-modified albumin, thiol balance, oxidative stress index, total antioxidant status, total oxidant status, and routine biochemical parameters. Methods: All participants were assessed with the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children. Total oxidant status, total antioxidant status, thiol balance, ischemia modified albumin, paraoxonase 1 activity, arylesterase activity, zinc and copper levels were measured by the spectrophotometric methods. Results: Compared to the control, the SLD group had statistically significantly lower values for PON1 antioxidant enzyme activity (p=.045), ARY antioxidant enzyme activity (p<.001), 25 OH Vitamin D (p=.005), reduced thiol ratio (p=.028), thiol oxidation reduction ratio (p=.01), native thiols (p=.024) and significantly higher values for total oxidant status (p=.017), oxidized thiol ratio (p=.028). Conclusion: The relationship between oxidative stress and SLD diagnosis in our results will be very important if it is supported by further new studies. In this case, evaluation of vitamin D, oxidative stress, antioxidant status and thiol balance may come to the agenda in the diagnosis and treatment of SLD.

Pomelo fruit wastes are potentially valuable antioxidants, anti-inflammatories, antihypertensives, and antihyperglycemics

Grapefruit (G) parts contain abundant phenolic acids and flavonoids (PPNs and FLVs). The wastes created from exocarps, mesocarps (G wastes, GW) and waste blanching water (WBW) lead to a considerable loss of PPNs and FLVs. Here, we assessed Buntan (CB), Buntan Hayata (CBH), and Peiyu (CP) cultivars and observed considerable amounts of PPNs and FLVs. The ethanolic extracts of GW (GWE) and WBW contained gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, ferulic acid, coumaric acid, naringin, hesperidin, diosmin, quercetin, hesperetin, nobiletin, and tangeretin (GWC). GWE has previously been reported to be a relatively active antioxidant, anti-inflammatory (based on the expression of TNF-α in Raw264.7 cells), antihypertensive, and anti-hyperglycemic compound. The IC50 values for antihyperglycemic activity with WBW for α-amylase were as follows: CB (27.96 ± 0.03 mg/mL) < CP (28.13 ± 0.19 mg/mL) < CBH (41.60 ± 0.16 mg/mL), and those for α-glucosidase were CB (1.80 ± 0.03 mg/mL) < CP (2.97 ± 0.29 mg/mL) < CBH (9.10 ± 0.51 mg/mL). GWC upregulated Glut4 in HepG2 cells, as well as the insulin secretion capability, and intracellular levels in RIN-m5F cells, and it downregulated DPP4 in HepG2 cells. The IC50 values for the angiotensin-converting enzyme activity were: CBP (5.10 ± 0.02 mg/mL) < CB (7.24 ± 0.65 mg/mL) < CP (8.60 ± 2.03 mg/mL). Our results indicate that PPNs and FLVs present in GW are worth reclaiming.

Acidification alters the functionality of metal polluted soils

Acidification can alter soil ecosystem functioning, thus jeopardizing the provision of valuable ecosystem services. Moreover, soil acidification can be accompanied by other soil threats, such as, for instance, metal pollution. The aim of this work was to assess to what extent acidification affects the functionality of metal polluted soils. To this aim, the pH of two soils (a highly metal polluted and a moderately metal polluted soil) was lowered by adding elemental sulphur at different doses, resulting in the following pH gradient in both soils: 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0 and 3.5. A variety of microbial indicators of soil health were measured in the treated soils: enzyme activities, substrate-induced respiration, microbial biomass carbon, bacterial and fungal abundances by qPCR, and bacterial and fungal richness by DGGE. Metal (Cd, Cu, Pb, Zn) bioavailability increased at decreasing pH values. The values of enzyme activities were strongly affected by acidification in both soils, followed by the values of soluble organic carbon in the highly polluted soil and bioavailable metal concentrations in the moderately polluted soil. These results improve our understanding of the role of microorganisms in the biogeochemical cycles of metal polluted acidic soils.

Hypomagnesemia and Its Relationship with Oxidative Stress Markers in Women with Breast Cancer.

Reduced serum magnesium concentrations in women with breast cancer compromises one of the antioxidant defense system involved in the carcinogenesis process. To evaluate parameters of magnesium, the enzyme activity of superoxide dismutase, and its relation with oxidative stress markers in women with breast cancer. A case-control study was conducted, involving 60 women in the age range between 29 and 65years, divided into two groups: women with breast cancer (n = 30) and women without breast cancer (n = 30). Plasma; ionized, erythrocytic, and urinary magnesium intake; plasma concentrations of thiobarbituric acid reactive substances; and erythrocyte superoxide dismutase enzyme activity were evaluated. The mean value of the amount of dietary magnesium was below the recommended level in both groups studied, with no statistical difference (p > 0.05). Plasma, ionized, and erythrocyte magnesium concentrations of women with breast cancer were reduced in relation to the control group (p < 0.0001) and inadequate according to the reference values. Urinary excretion was high, with a significant difference between groups (p < 0.0001). The mean concentration of thiobarbituric acid reactive substances was high in the study participants, with no significant statistical difference between the groups (p > 0.05). The mean values of superoxide dismutase enzyme activity were adequate, with no statistically significant difference between the groups (p > 0.05). Women with breast cancer have impaired magnesium homeostasis, characterized by its reduction in diet, plasma, and erythrocytes and its increase in urine.

Chitinase activity potential and identification of chitinolytic bacteria isolated of swimmer crab’s cell

This study aimed at investigating the chitinase enzyme activity produced by chitinolytic bacteria from the skin of blue swimmer crab (Portunus pelagicus) and identification of the genus isolate. This study consists of two stages: firstly, the qualitative and quantitative activity of the chitinase enzyme; and secondly, biochemical identification of the bacteria. The quantitative chitinase enzyme activity is measured using the UV-Vis spectrophotometer UV-Vis at the wavelength at 660 nm. The chitinase enzyme is obtained from the isolation of chitinolytic bacteria cultured within a media to grow solid chitin, which contains colloidal chitin substrate as chitinase inductor at the temperature of 30°C. The highest chitinolytic activity is obtained from the 24 h supernatant culture, with a value of enzyme activity at 0.149 U/mL. Macroscopic and microscopic identification showed that the chitinolytic bacteria isolate R1, whereas the biochemical cell shows the characteristics of the genus Pseudomonas. Keywords: biodegradable, chitinase, spectrophotometer, Portunus pelagicus, Pseudomonas DOI: 10.25165/j.ijabe.20211403.5273 Citation: Sulistijowati R, Sudin, Harmain R M. Chitinase activity potential and identification of chitinolytic bacteria isolated of swimmer crab’s cell. Int J Agric & Biol Eng, 2021; 14(3): 228–231.

Actividad glutatión peroxidasa en vacas lecheras sin suplementar y suplementadas con selenio

&lt;p&gt;El objetivo del presente trabajo fue evaluar los niveles de la actividad glutatión-peroxidasa&lt;br /&gt;(GPX) en vacas lecheras suplementadas y sin suplementar con selenio (Se) intra-ruminal.&lt;br /&gt;Se determinó la actividad GPX de 96 vacas Holstein primíparas y multíparas, clínicamente&lt;br /&gt;sanas, procedentes de un establecimiento comercial de la localidad de Centeno, Provincia de&lt;br /&gt;Santa Fe (Argentina). Se definieron dos categorías de reses según las determinaciones individuales de GPX tomando como valor de corte 130 U/gHb. Los animales de cada categoría se dividieron aleatoriamente en dos subgrupos, uno de los cuales recibió un bolo intraruminal&lt;br /&gt;de Se de larga acción (Permatrace®) mientras que el otro permaneció sin suplementar. A&lt;br /&gt;continuación, se efectuaron dos nuevas determinaciones de la actividad enzimática: preparto&lt;br /&gt;(entre los 30 y los 15 días previos al parto) y posparto (entre los 30 y los 45 posteriores al&lt;br /&gt;parto). El 35,4% de las vacas presentó valores de actividad de la enzima menores al valor de&lt;br /&gt;corte. Los animales con bajos valores basales de actividad GPX no suplementadas con bolos&lt;br /&gt;de Se, no modificaron significativamente los datos basales. En las vacas con bajos valores&lt;br /&gt;basales de actividad GPX y suplementadas con Se, se observó un aumento significativo de la&lt;br /&gt;actividad enzimática. Se concluye que una proporción importante de animales presenta baja&lt;br /&gt;actividad GPX, que los niveles de las enzimas se modifican según el momento de la evaluación&lt;br /&gt;en relación al tiempo del parto, y que la suplementación con bolos de Se intra-ruminal&lt;br /&gt;constituye una estrategia efectiva para aumentar la actividad de la enzima.&lt;/p&gt;

Efficiency of leaf litter mulch in the restoration of soil physiochemical properties and enzyme activities in temporary skid roads in mixed high forests

Various engineering measures, such as mulching, have been applied on decommissioned skid trails to suppress the adverse effects of overland flow and flood hazards. However, very little research has been done on the effects of such treatments on soil recovery. The aim of this study is to determine the effectiveness of different leaf litter levels on the restoration of soil properties and enzyme activity, when spread on decommissioned skid trails over a four-year period after soil compaction. In total, 90 soil samples in 18 runoff plots were measured under six treatments, including undisturbed (control) treatment, UND; untreated skid trail, U; and four levels of leaf litter, LML1, LML2, LML3, and LML4, with levels of 0.42, 0.81, 1.31, and 1.69 kg m−2, respectively. Soil bulk density and penetration resistance under the litter mulch treatments were lower than that under the U treatment, and at the lowest in the UND treatment. The total porosity, macroporosity, and aggregate stability were at the highest level in UND, followed by LML4 ≈ LML3 > LML2 ≈ LML1. Soil organic C, total N, C/N ratio, C and N sequestration, available nutrients (i.e., P, K, Ca, and Mg), and fulvic and humic acids were at the highest level in UND followed by LML4, and at the lowest level in U followed by LML1 ≈ LML2. The highest earthworm density and dry mass, fine root biomass, soil microbial respiration, microbial biomass carbon, NH4+, NO3−, nitrogen mineralization, and microbial biomass nitrogen were measured in UND, followed by LML4. Compared with U, all litter mulch treatments enhanced enzyme activity. Four years after mulch application, the values of soil biological and microbial properties and enzyme activity were significantly higher in LML4 ≈ LML3 followed by LML2 ≈ LML1, compared to U, but were still lower than the values of the UND treatment. We can conclude that the increased levels of leaf litter mulch moderately improved soil physio-chemical, biological, and microbial properties, as well as enzyme activity, after mechanized operations over a four year period, compared to the U treatment. However, the values of soil properties and enzyme activity were still lower than those in the UND treatment, indicating that four years is not long enough to restore the soil properties to pre-harvest levels in the study area. In conclusion, leaf litter level of LML3 with 1.31 kg m−2 can be applied as an optimal level for spreading leaf litter on skid trails to modify and enhance soil quality.

Optimum growth conditions of Lactobacillus brevis LIPI13-2-LAB131 in β-galactosidase enzyme production

Abstract. Indah AWN, Rohmatussolihat, Rahayu WP, Setyoningrum F, Priadi G, Afianti F. 2020. Optimum growth conditions of Lactobacillus brevis LIPI13-2-LAB131 in β-galactosidase enzyme production. Biodiversitas 21: 5403-5407. Deficiency of β-galactosidase enzyme causes lactose to become undigested in gastrointestinal system, therefore the system needs further addition of external β-galactosidase. The sources β-galactosidase enzyme varies from plants, animals, and microorganisms. In industrial applications, microorganisms have become a considered potential source of β-galactosidase. Lactobacillus brevis LIPI13-2-LAB131 had high β-galactosidase enzyme activity, which was 7.93 U/mL. The aim of this research was to optimize the growth condition of L. brevis LIPI13-2-LAB131 in order to produce maximum β-galactosidase enzyme activity. This research consisted of performing optimization processes using design expert 7.0 (DX7) program with response surface methodology (RSM) and partial purification of β-galactosidase enzyme. The results of this research showed that the optimum growth conditions of L. brevis LIPI13-2-LAB131 were in 1.48% lactose level, incubation temperature of 34.91 °C, incubation time of 48.48 hours, and 2.83% inoculum size with desirability value of 0.839. The result of enzyme purification showed that value of β-galactosidase enzyme activity increased up to 22.88 ± 0.29 U/mL with purification yield of 11.65%.

Relationship Among NAGase Enzyme Activity, CMT Score and Somatic Cell Count in Milk of Crossbred Dairy Cows with Sub-Clinical Mastitis in North-Western Province of Sri Lanka

The assay procedure for N-acetyl-β-D-glucosaminidase (NAGase) was considered to be the most reliable, simple, and rapid enzymatic method for estimating the severity of mammary tissue damage. This study was carried out to assess the relationship of NAGase enzyme activity, California mastitis test score (CMTS) and somatic cell counts (SCC) in milk and the influence of breed, parity and age of the cow on NAGase activity. The results showed that prevalence of sub-clinical mastitis (SCM) was 74.5% (41/55) in the population of cows tested. The isolated pathogens were Staphylococcus spp. (34%, 14/41), Escherichia coli (34%, 14/41) and Streptococcus spp. (32%, 13/41). The SCC showed a significant (p<0.05) positive correlation with the activity of NAGase (R2= 0.796) and CMTS (R2= 0.709). A significant correlation was observed between the NAGase activity and SCC in SCM positive milk, where the correlation was stronger (R2= 0.748) in the former than in the latter. The parity (R2= 0.843) and age (R2= 0.758) of the cow also showed a significant (p<0.05) positive correlation with enzyme activity. The mean SCC and enzyme activity of different crossbreds of the study population did not show a significant correlation, but mean values of SCC and enzyme activity were higher when an animal was phenotypically more related to European breeds (779– 1848 x103 SCC/ml;0.64 -0.89 μmole/min/ml) than tropical breeds (427–534x103 SCC/ml; 0.26-0.43 μmole/min/ml). It could be concluded that, the prevalence of SCM in crossbred cows in North-Western Province of Sri Lanka is considerably high. The determination of NAGase enzyme activity in milk could be used as a method for early detection of SCM more accurately than CMTS and SCC.

Cocoa (Theobroma cacao L.) Seed Proteins' Anti-Obesity Potential through Lipase Inhibition Using In Silico, In Vitro and In Vivo Models.

The aim of this study was to determine the pancreatic lipase (PL) inhibitory effect of cocoa protein (CP) hydrolysates (CPH) using in silico and in vitro approaches, and an in vivo high-fat diet (HF) obese rat model. The results showed better theoretical affinity on PL for cocoa peptides EEQR, GGER, QTGVQ, and VSTDVNIE released from vicilin and albumins (−6.5, −6.3, −6.2, and −6.1 kcal/mol, respectively). Absorption, distribution, metabolism, and excretion (ADMET) prediction showed the human intestinal absorption (HIA) capacity of orlistat and eight cocoa peptides, demonstrating that they presented a low probability of toxicity with values lower than 0.6, while the orlistat has a high probability of hepatotoxicity with a mean value of 0.9. CPH (degree of hydrolysis of 55%) inhibited PL with an IC50 (concentration needed to inhibit 50% of enzyme activity) value of 1.38 mg/mL. The intragastric administration of 150 mg CP/kg/day to rats increased total lipids and triglycerides excretion in feces, ranging from 11% to 15% compared to the HF-diet. The HF + CP-diet also significantly decreased (p < 0.05) the apparent rate of fat absorption compared with the HF group. These results suggest that CP has anti-obesity potential by inhibiting PL, thus helping to prevent the development of non-communicable diseases.

Assessment of biological indicators of soil quality to enhance productivity of pulse crops

An assessment of biological indicators of soil quality was conducted in three blocks of pulse growing zones of Virudhunagar district viz., Sattur, Aruppukottai and Tiruchuli which were classified into three categories viz., low yielding (less than 400 kg ha-1), medium (400 to 700 kg ha-1) and high yielding (more than 700 kg ha-1) zones. The biological indicators viz., soil organic carbon content, microbial respiration rate and dehydrogenase enzyme activity of soil were assessed for each zone. The low organic carbon content (1.74 g kg-1) in the low yielding zone reflected in the low mean soil respiration rate of 2.34 mg CO2 kg-1d-1. In the high yielding zones, the respiration rate ranged from 2.45 to 7.45 mg CO2 kg-1d-1 with a mean value of 4.48 mg CO2 kg-1d-1. About 70 percent soil samples from high yielding zone recorded high soil respiration rate. The average values of dehydrogenase enzyme activity was higher in 82% of high quality soils where the farmers have practised proper nutrient management practices indicating that regular application of enriched FYM, Azospirillum and pulse wonder along with TNAU recommended dosage of fertilizers enhanced the yield and productivity of pulses.