Functional classification of esterases from leaves of Aspidosperma polyneuron M. Arg. (Apocynaceae)

Esterases as emerging biocatalysts: Mechanistic insights, genomic and metagenomic, immobilization, and biotechnological applications

Esterase enzymes are a family of hydrolases that catalyze the breakdown and formation of ester bonds. Esterases have gained a prominent position in today's world's industrial enzymes market. Due to their unique biocatalytic attributes, esterases contribute to environmentally sustainable design approaches, including biomass degradation, food and feed industry, dairy, clothing, agrochemical (herbicides, insecticides), bioremediation, biosensor development, anticancer, antitumor, gene therapy, and diagnostic purposes. Esterases can be isolated by a diverse range of mammalian tissues, animals, and microorganisms. The isolation of extremophilic esterases increases the interest of researchers in the extraction and utilization of these enzymes at the industrial level. Genomic, metagenomic, and immobilization techniques have opened innovative ways to extract esterases and utilize them for a longer time to take advantage of their beneficial activities. The current study discusses the types of esterases, metagenomic studies for exploring new esterases, and their biomedical applications in different industrial sectors.

Evaluation of phytotoxicity, cytotoxicity, and genotoxicity of ZnO nanoparticles in Vicia faba

Due to the accelerating use of manufactured nanomaterials, more research is needed to define their impact on plants. The present investigation aimed at evaluating the effect of different levels (0.0, 10, 25, 50, and 100 mg/L) of ZnO nanoparticles (NPs) on Vicia faba during seed germination and seedling establishment. Additionally, V. faba root meristems were used as a model to monitor the cytotoxic and genotoxic effects resulting from exposure to ZnO NPs. The influence of ZnO NPs on three isoenzyme systems, peroxidase, α, and β esterase, was also evaluated using native-PAGE. Our results showed that lower concentrations of ZnO NPs (especially 10 and 25 mg/L) enhanced seed germination and improved seedling growth, while higher concentrations (100 and 200 mg/L) resulted in phytotoxicity. Cytological investigations of ZnO NPs-treated V. faba root cells denoted the clastogenic and aneugenic nature of ZnO NPs. Differential increase in mitotic index and significant alterations in cell cycle were observed upon exposure to ZnO NPs. High concentrations of ZnO NPs markedly induced chromosomal aberration, micronuclei, and vacuolated nuclei formation. Chromosomal breakage, chromosomal bridges, ring chromosomes, laggard chromosomes, and stickiness were also observed at a higher rate. The PAGE analysis showed that ZnO NPs treatments altered the expression patterns of all studied enzyme systems. Collectively, results from this work will help to further understand the phytotoxic effects of nanomaterials.

Insecticide resistance mapping in the vector of lymphatic filariasis, Culex quinquefasciatus Say from northern region of West Bengal, India

Culex quinquefasciatus is a vector of lymphatic filariasis and vector control strategies normally involve the use of synthetic insecticides targeted against them. Extensive and uncontrolled use of these synthetic insecticides has led to the development of insecticide resistance in the mosquito vectors. In this context, to study the resistance status of Cx. quinquefasciatus, field populations were collected from three districts of Northern part of West Bengal and tested against insecticides (5% malathion, 0.05% deltamethrin, 0.05% lambdacyhalothrin,0.75% permethrin, 0.1% propoxur, 4% DDT and Temephos). Qualitative and quantitative enzyme assay was also conducted in order to find the role of detoxifying enzymes behind the development of insecticide resistance. This study revealed the presence of widespread resistance amongst the field populations of Cx. quinquefasciatus throughout the studied regions. Moreover, the result of native PAGE and biochemical enzyme assay may be linked to some extent in the involvement of the detoxifying enzymes in conferring resistance against insecticides in most of the tested Cx. quinquefasciatus populations. The present study involving the survey of resistance status may be of immense help during the implementation of vector control strategies throughout this region.

Esterase and peroxidase isoforms in different stages of morphogenesis in Fritillaria meleagris L. in bulb-scale culture

Morphogenesis in vitro is a complex and still poorly defined process. We investigated esterase and peroxidase isoforms detected in bulb scale, during Fritillaria meleagris morphogenesis. Bulbs were grown either at 4 °C or on a medium with an increased concentration of sucrose (4.5%) for 30 days. After these pre-treatments, the bulb scales were further grown on nutrient media that contained different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin (KIN) or thidiazuron (TDZ). Regeneration of somatic embryos and bulblets occurred at the same explant. The highest numbers of somatic embryos and bulblets were regenerated on the medium containing 2,4-D and KIN (1mg/L each), while morphogenesis was most successful at a TDZ concentration between 0.5 and 1mg/L. Monitoring of esterases and peroxidases was performed by growing bulb scales on a medium enriched with 2,4-D and KIN or TDZ (1mg/L), and the number and activity of isoforms were followed every 7 days for 4 weeks. In control explants, six isoforms of esterase were observed. Three isoforms of peroxidase were not detected in the control bulb scale, which has not begun its morphogenesis process.

Extraction and purification of wheat-esterase using aqueous two-phase systems of ionic liquid and salt

To explore a new and simple rapid extraction and purification technique for wheat-esterase, an ionic liquids (ILs)-based aqueous two-phase system (ATPS) was developed for the purification of wheat-esterase from wheat extracts. Effects of various process parameters such as the concentrations of [Bmim]BF4, the types and concentrations of phase-forming salt, the system pH and the temperature on partitioning of wheat-esterase were evaluated. The obtained data indicated that wheat-esterase was preferentially partitioned into the ILs-rich phase and the ATPS composed of 20 % [Bmim]BF4 (w/w) and 25 % (w/w) NaH2PO4(pH = 4.8) showed good selectivity on wheat-esterase. Under the optimum conditions, wheat-esterase was purified with an acceptable yield (88.93 %), but produced wheat-esterase was 4.23 times as pure. It was obvious that temperature shows little influence on the purification between 10 and 50 °C. Sephadex G-150FF revealed that the band intensity of contaminating proteins in ATPS fraction almost disappeared. Therefore, ILs-based ATPS was an effective method for partitioning and recovery of wheat-esterase from wheat crude extracts.

Genetic diversity analysis of Capsicum spp germplasm bank accessions based on α/β-esterase polymorphism

Genetic diversity and structure were analyzed in 10 accessions belonging to Banco Ativo de Germoplasma de Capsicum located at Federal University of Piauí in northwestern Brazil that receives pepper samples grown in community gardens in various regions and Brazilian states. Selections were made from seeds of C. chinense (4 accessions), C. annuum (5 accessions), and C. baccatum (1 accession). Samples consisting of leaves were collected from 4-10 plants of each accession (a total of 85 plants). Native polyacrylamide gel electrophoresis was used to identify α- and β-esterase polymorphisms. Polymorphism was clearly detected in 5 loci. Sixteen alleles were found at 5 α/β-esterase loci of the three Capsicum species. In the C. chinense samples, the highest HO and HE values were 0.3625 and 0.4395, respectively, whereas in C. annuum samples, HO and HE values were 0.2980 and 0.3310, respectively; the estimated HO and HE values in C. chinense samples were higher than those detected in C. annuum samples. A deficit of homozygous individuals was found in C. chinense (FIS = -0.6978) and C. annuum (FIS = 0.7750). Genetic differentiation between C. chinense and C. annuum at these loci was high (FST = 0.1867) indicating that C. chinense and C. annuum are genetically structured species for α/β- esterase isozymes. The esterase analysis showed high genetic diversity among the C. chinense and C. annuum samples and very high genetic differentiation (FST = 0.6321) among the C. chinense and C. annuum samples and the C. baccatum accession.

Biochemical and genetic polymorphisms for carboxylesterase and acetylesterase in grape clones of Vitis vinifera L. (Vitaceae) cultivars

Native polyacrylamide gel electrophoresis (PAGE) was employed to show the highest number of esterase loci and to detect alpha- and beta-esterase polymorphisms in leaf buds of Vitis vinifera cultivars. A total of 16 esterase isozymes were detected in leaf buds from 235 plants including Italia, Rubi, Benitaka, and Brasil cultivars. Biochemical characterization of the grape esterases using ester substrates revealed alpha-, beta-, and alpha/beta-esterases with inhibitor tests distinguishing both carboxylesterases (EST-2, EST-3, EST-5, EST-6, EST-7, EST-8, EST-9, EST-10, and EST-16 isozymes) and acetylesterases (EST-4, EST-11, EST-12, EST-13, EST-14, EST-15 isozymes). No allele variation for alpha-, beta-, and alpha/beta-esterases was detected; however, EST-3 alpha-carboxylesterase was absent in 61.7% of vines, and EST-4 alpha/beta-acetylesterase was absent in one vine of Rubi cv. Null EST-3 carboxylesterase phenotype (61.7%) cannot be explained in this article, but the high genetic polymorphism in four V. vinifera clones is a positive aspect for genetic selection and development of new clones with different characteristics.

A novel phenotype based on esterase electrophoretic polymorphism for the differentiation of Lactococcus lactis ssp. lactis and cremoris

AIMS

To evaluate the esterase phenotype in Lactococcus lactis strains isolated from traditional Tunisian dairy products.

METHODS AND RESULTS

A collection of 55 L. lactis strains isolated from traditional fermented milk products and three reference strains were identified at species and subspecies level using molecular methods targeted to the 16S rRNA gene and to the histidine operon. The genotypic data obtained allowed the identification of the strains as L. lactis ssp. lactis and L. lactis ssp. cremoris with the prevalence of the ssp. lactis. The phenotypic identification based on arginine hydrolysis, the growth at 40 degrees C and in presence of 4% NaCl showed several discrepancy with the identification data based on genotypic analysis. Additional experiments carried out evaluating the esterase electrophoretic patterns revealed four classes of esterases identified on the basis of their electrophoretic mobility and specific activity on alpha- and beta-naphthyl ester of acetate and propionate. Esterase profiles discriminated the strains in two main groups corresponding to the subspecies cremoris and lactis according to a DNA-based identification.

CONCLUSIONS

The evaluation of esterase activity represents a novel phenotype for the taxonomic discrimination of the L. lactis ssp. lactis and cremoris.

SIGNIFICANCE AND IMPACT OF THE STUDY

Besides the DNA-based techniques that allow the rapid and accurate species/subspecies identification, the electrophoretic esterase profiles of L. lactis strains represents: (i) a new phenotypic tool to understand the physiology and the ecology of this species; and (ii) a new test for the potential selection of flavour producing strains.

Protein, leucine aminopeptidase, esterase, acid phosphatase and photosynthetic responses of oleander (Nerium oleander L.) during cold acclimation and freezing treatments

Six-month-old oleander (Nerium oleander L.) pot plants, derived from vegetative propagation by cuttings, were tested for their ability to cold hardening. Damage of the non-acclimated (NA) plants was visible when treated by low freezing temperatures (below -2 degrees C). The responses of total proteins, leucine aminopeptidase (LAP), esterase (EST) and acid phosphatase (ACP) isoforms of NA and cold-acclimated (CA; 4 degrees C for 14 days) plants were compared using polyacrylamide gel electrophoresis. These molecular markers were also compared in NA and CA plants which received for 2h temperatures of 0, -2, -4, -6 and -8 degrees C. A new 38-kDa polypeptide appeared from day 7 to 14 during the acclimation treatment in the bark extracts and on day 14 in the leaf extracts. The above-mentioned polypeptide band (38 kDa) strongly appeared in all freezing treatments (0, -2, -4, -6 and -8 degrees C) in both bark and leaf extracts of the CA plants. Alterations in the number and the intensity of LAP and EST isoforms as well as in the intensity of ACP isoforms were observed in both bark and leaf of the CA oleander plants. A newly expressed EST isoform is proposed as biochemical marker for the cold acclimation treatment. CO2 assimilation rates (A) as well as transpiration rates (E) in NA plants were positive in 0 degrees C and negative in all temperatures below zero in the freezing treatments. In contrast, CO2 assimilation rates (A) and transpiration rates (E) were positive in CA plants in all temperatures of freezing treatment. A significant decrease (P<0.05) in chlorophyll (Chl) a, Chl a+b concentration and Chl a/b ratio were noticed in oleander plants during the acclimation treatment (from day 0 to 14), while Chl b concentration was unchanged at the respective time. On the other hand, no significant (P<0.05) differences were observed in the freezing treatments.