Genetic diversity and forensic statistical support for the 12 X-STR markers in the Malaysian Indian population using Qiagen Investigator® Argus X-12 QS kit.

X-chromosome short tandem repeats (X-STRs) are useful for human identification, especially in complex kinship scenarios. Since forensic statistical parameters vary among populations and the X-STRs population data for the diverse population of Peninsular Malaysia's are unavailable, this attempt for Indians (n = 201) appears forensically relevant to support the 12 X-STRs markers' evidential value for human identification in Malaysia. The Qiagen Investigator® Argus X-12 QS kit showed that DXS10135 was the most polymorphic locus with high genetic diversity, polymorphism information richness, heterozygosity, and exclusion power. Based on allele frequencies, the strength of discrimination and mean exclusion chance (MECKrüger, MECKishida, MECDesmarais, and MECDesmaraisDuo) values for the Malaysian Indians were ≥0.999997790686228. As for haplotype frequencies, the overall discrimination power and mean exclusion probability (MECKrüger, MECKishida, MECDesmarais, and MECDesmaraisDuo) were ≥0.9999984801951. The genetic distance, neighbor-joining phylogenetic tree, and principal component analysis also supported the evidential value of the 12 X-STRs markers for forensic practical caseworks in Malaysia.

Developing criteria for a profession to be considered as profession of allied health in Malaysia: a qualitative study from the Malaysian perspective.

BACKGROUND: The Malaysian Allied Health Profession Act (Act 774) regulates the practice of allied health practitioners in Malaysia, with two described professions viz. allied health profession (AHP) and profession of allied health (PAH). While AHPs have been clearly identified by the law, comprehensive implementation of the act requires development of specific criteria in defining any profession as PAH in the Malaysian context. Hence, the research aims to explore and identify the criteria for defining such professions for healthcare policy direction in Malaysia. METHODS: This research utilised two methods of qualitative research (document review and focus group discussions (FGDs) involving 25 participants from four stakeholders (higher education providers, employers, associations and regulatory bodies). Both deductive and inductive thematic content analysis were used to explore, develop and define emergent codes, examined along with existing knowledge on the subject matter. RESULTS: Sixteen codes emerged from the FGDs, with risk of harm, set of competency and skills, formal qualification, defined scope of practice, relevant training and professional working within the healthcare team being the six most frequent codes. The frequencies for these six codes were 62, 46, 40, 37, 36 and 18, correspondingly. The risk of harm towards patients was directly or indirectly involved with patient handling and also relates to the potential harms that may implicate the practitioners themselves in performing their responsibilities as the important criterion highlighted in the present research, followed by set of competency and skills. CONCLUSIONS: For defining the PAH in Malaysia, the emerged criteria appear interrelated and co-exist in milieu, especially for the risk of harm and set of competency and skills, with no single criterion that can define PAH fully. Hence, the integration of all the empirically identified criteria must be considered to adequately define the PAH. As such, the findings must be duly considered by policymakers in performing suitable consolidation of healthcare governance to formulate the appropriate regulations and policies for promoting the enhanced framework of allied health practitioners in Malaysia.

An Overview of Crosslinked Enzyme Aggregates: Concept of Development and Trends of Applications.

Enzymes are commonly used as biocatalysts for various biological and chemical processes in industrial applications. However, their limited operational stability, catalytic efficiency, poor reusability, and high-cost hamper further industrial usage. Thus, crosslinked enzyme aggregates (CLEAs) are developed as a better enzyme immobilization tool to extend the enzymes' operational stability. This immobilization method is appealing because it is simpler due to the absence of ballast and permits the collective use of crude enzyme cocktails. CLEAs, so far, have been successfully developed using a variety of enzymes, viz., hydrolases, proteases, amidases, lipases, esterases, and oxidoreductase. Recent years have seen the emergence of novel strategies for preparing better CLEAs, which include the combi- and multi-CLEAs, magnetics CLEAs, and porous CLEAs for various industrial applications, viz., laundry detergents, organic synthesis, food industries, pharmaceutical applications, oils, and biodiesel production. To better understand the different strategies for CLEAs' development, this review explores these strategies and highlights the relevant concerns in designing innovative CLEAs. This article also details the challenges faced during CLEAs preparation and solutions for overcoming them. Finally, the trending strategies to improve the preparation of CLEAs alongside their industrial application trends are also discussed.

Internal validation of reduced PCR reaction volume of the Qiagen Investigator® Argus X-12 QS Kit from blood samples on FTA cards.

The onus of proof in criminal cases is beyond any reasonable doubt, and the issue on the lack of complete internal validation data can be manipulated when it comes to justifying the validity and reliability of the X-chromosomal short tandem repeats analysis for court representation. Therefore, this research evaluated the efficiency of the optimized 60% reduced volumes for polymerase chain reaction (PCR) amplification using the Qiagen Investigator® Argus X-12 QS Kit, as well as the capillary electrophoresis (CE) sample preparation for blood samples on Flinder's Technology Associates (FTA) cards. Good-quality DNA profile (3000-12,000 RFU) from the purified blood sample on FTA card (1.2 mm) were obtained using the optimized PCR (10.0 µL of PCR reaction volume and 21 cycles) and CE (9.0 µL Hi-Di™ Formamide and 0.3 µL DNA Size Standard 550 [BTO] and 27 s injection time) conditions. The analytical and stochastic thresholds were 100 and 200 RFU, respectively. Hence, the internal validation data supported the use of the optimized 60% reduced PCR amplification reaction volume of the Qiagen Investigator® Argus X-12 QS Kit as well as the CE sample preparation for producing reliable DNA profiles that comply with the quality assurance standards for forensic DNA testing laboratories, while optimizing the analytical cost.

Interaction of the nanobio-based reagent with sodium fluorescein and lipids via bioinformatics for forensic fingerprint visualisations.

Being commonly found at crime scenes, fingerprints are crucial for human identification, attributable to their uniqueness, persistence and systematic classification of ridge patterns. In addition to latent fingerprints being invisible to the naked eye, the escalating trends of disposing forensic evidence bearing such prints in watery bodies would further complicate criminal investigations. Taking into account the toxicity of small particle reagent (SPR) commonly used in visualising latent fingerprints on wet and non-porous objects, a greener alternative using the nanobio-based reagent (NBR) has been suggested. However, NBR only applies to white and/or relatively light-coloured objects. Thus, conjugation of sodium fluorescein dye with NBR (f-NBR) may be beneficial for increasing the contrast of fingerprint on multi-colored objects. Hence, this study was aimed at investigating the possibility of such conjugation (i.e., f-NBR) as well as proposing suitable interactions between the f-NBR and lipid constituents of fingerprints (tetra-, hexa- and octadecanoic acids) via molecular docking and molecular dynamics simulations. The binding energies between CRL with its ligands were observed at -8.1, -5.0, -4.9 and -3.6 kcal/mole for sodium fluorescein, tetra-, hexa- and octadecanoic acids, respectively. Besides, the formations of hydrogen bonds observed in all complexes (ranged between 2.6 and 3.4 Å), further supported by the stabilized root mean square deviation (RMSDs) plots in MD simulations. In short, the conjugation of f-NBR was computationally feasible, and thereby merits further investigations in the laboratory.Communicated by Ramaswamy H. Sarma.

Preliminary forensic assessment of the visualised fingerprints on nonporous substrates immersed in water using the green and optimised novel nanobio-based reagent.

The discovery of forensic evidence (e.g. weapons) during forensic underwater investigations has seen an increasing trend. To date, small particle reagent (SPR) has been one of the routinely used methods for visualising fingerprints on wet, non-porous substrates. However, the long term use of SPR is detrimental to humans and environment due to the use of toxic chemicals. Although previously we have successfully developed and optimised a greener nanobio-based reagent (NBR), its suitable practical use in a more realistic scene (e.g. outdoor pond) was not evaluated. Therefore, this present research is aimed at (1) investigating the performance of NBR against the benchmark SPR in visualising fingerprints immersed in a natural outdoor pond and (2) evaluating the greenness of NBR against the analytical Eco-Scale. Results showed that the performance of the optimised NBR was mostly comparable (University of Canberra (UC) comparative scale: 0) with SPR at visualising fingerprints on three different non-porous substrates immersed in a natural outdoor pond. Observably, the NBR had higher preference towards aged fingerprints (up to 4 weeks of immersion). In addition, its greenness assessment revealed 76 points, indicating 'excellent green analysis'. The findings gathered here further supported the practical use of the NBR in forensic investigations.

Counterfeit fifty Ringgit Malaysian banknotes authentication using novel graph-based chemometrics method.

Counterfeiting, in particular, the forgery of banknotes is a serious crime problem and has become a great challenge to the global economies. The forensic science experts have been utilizing chemical technique such as infrared spectroscopy to analyze genuine and counterfeit banknotes. Nevertheless, chemometrics techniques are required to further discriminate the banknotes. In this paper, an advanced fuzzy graph chemometrics method is used to discriminate genuine and counterfeit fifty Ringgit Malaysian (RM50) banknotes. The development of the technique, namely chemometrics fuzzy autocatalytic set (c-FACS) is presented in this paper, together with the results and its comparison to principal component analysis (PCA) method. The results from the c-FACS analysis showed distinct patterns and features of the counterfeit banknotes in the c-FACS plot. Furthermore, the new method is faster than PCA in authentication analysis of counterfeit banknotes. Hence, the c-FACS provides better performance in terms of computing time as compared to PCA, and has the potential in assisting the investigation involving counterfeit banknotes.

Occurrence of heavy metals and their removal in Perna viridis mussels using chemical methods: a review.

Despite the nutritional benefits, bivalves like mussels are also an excellent aquatic heavy metal biomonitoring agent due to their high tolerance to varying levels of temperature, salinity and oxygen, as well as pollutants. Although the accumulated toxic heavy metals may not exert direct negative impacts on the mussels, such toxicants in mussel tissues can give harmful effects on human body when consumed in toxic quantities and/or over prolonged period. The booming of urban and industrial activities, and consequently the increment of runoffs, as well as wastewater effluents and leaching, further exacerbated the magnitude of this issue. Hence, continuous monitoring of heavy metal contents in mussels is vital to ensure its compliance with food safety regulations, protecting consumers at large. This review paper discusses the occurrence of heavy metals in mussels especially that of Perna viridis in Malaysia and other parts of the world since year 2000 until 2021. Heavy metal concentration data and patterns from various coastal and/or estuaries were compared. Where applicable, statistical data that indicate variations between sampling sites, sampling months or years and chemical treatments for heavy metal removal were critically reviewed. Health risk assessment findings were also discussed. More importantly, related chemical-based interventions to minimize and/or eliminate toxic heavy metals from mussels are also reviewed.

Ternary biogenic silica/magnetite/graphene oxide composite for the hyperactivation of Candida rugosa lipase in the esterification production of ethyl valerate.

Oil palm leaves (OPL) silica (SiO2) can replace the energy-intensive, commercially produced SiO2. Moreover, the agronomically sourced biogenic SiO2 is more biocompatible and cost-effective enzyme support, which properties could be improved by the addition of magnetite (Fe3O4) and graphene oxide (GO) to yield better ternary support to immobilize enzymes, i.e., Candida rugosa lipase (CRL). This study aimed to optimize the Candida rugosa lipase (CRL immobilization onto the ternary OPL-silica-magnetite (Fe3O4)-GO (SiO2/Fe3O4/GO) support, for use as biocatalyst for ethyl valerate (EV) production. Notably, this is the first study detailing the CRL/SiO2/Fe3O4/GO biocatalyst preparation for rapid and high yield production of ethyl valerate (EV). AFM and FESEM micrographs revealed globules of CRL covalently bound to GL-A-SiO2/Fe3O4/GO; similar to Raman and UV-spectroscopy results. FTIR spectra revealed amide bonds at 3478 cm-1 and 1640 cm-1 from covalent interactions between CRL and GL-A-SiO2/Fe3O4/GO. Optimum immobilization conditions were 4% (v/v) glutaraldehyde, 8 mg/mL CRL, at 16 h stirring in 150 mM NaCl at 30 °C, offering 24.78 ± 0.26 mg/g protein (specific activity = 65.24 ± 0.88 U/g). The CRL/SiO2/Fe3O4/GO yielded 77.43 ± 1.04 % of EV compared to free CRL (48.75 ± 0.70 %), verifying the suitability of SiO2/Fe3O4/GO to hyperactivate and stabilize CRL for satisfactory EV production.

The Psychology of Murder Concealment Acts.

The escalating trend of murder victim concealment worldwide appears worrying, and literature does not reveal any specific study focusing on victim concealment amongst convicted male Malaysian murderers. Therefore, this study was aimed at investigating the psychological traits that may underlie the act of murder concealment in Malaysia via mixed method approaches. Male murderers (n = 71) from 11 prisons were selected via purposive sampling technique. In the quantitative analysis, a cross-sectional study design using the validated questionnaire was used. The questionnaire contained murder concealment variables and four Malay validated psychometric instruments measuring: personality traits, self-control, aggression, and cognitive distortion. The independent sample t-tests revealed the significantly higher level of anger in murderers who did not commit concealment acts (8.55 ± 2.85, p < 0.05) when compared with those who did so (6.40 ± 2.64). Meanwhile, the Kruskal-Wallis H test revealed that anger and the personality trait of aggressiveness-hostility significantly varied across the different groups of murder concealment acts (p < 0.05). The qualitative data obtained via the in-depth interviews revealed two important themes for the murderers to commit murder concealment acts: (1) fear of discovery and punishment and (2) blaming others. These findings discussed from the perspectives of the murderers within the context of criminology and psychology may provide the first ever insight into the murder concealment acts in Malaysia that can benefit the relevant authorities for crime prevention and investigation efforts.

Antioxidant Activity Evaluation of FlexirubinType Pigment from Chryseobacterium artocarpi CECT 8497 and Related Docking Study.

The current research is focused on studying the biological efficacy of flexirubin, a pigment extracted from Chryseobacterium artocarpi CECT 8497.Different methods such as DPPH, H2O2, NO•, O2•-, •OH, lipid peroxidation inhibition by FTC and TBA, ferric reducing and ferrous chelating activity were carried out to evaluate the antioxidant activity of flexirubin. Molecular docking was also carried out, seeking the molecular interactions of flexirubin and a standard antioxidant compound with SOD enzyme to figure out the possible flexirubin activity mechanism. The new findings revealed that the highest level of flexirubin exhibited similar antioxidant activity as that of the standard compound according to the H2O2, •OH, O2•-, FTC and TBA methods. On the other hand, flexirubin at the highest level has shown lower antioxidant activity than the positive control according to the DPPH and NO• and even much lower when measured by the FRAP method. Molecular docking showed that the interaction of flexirubin was in the binding cavity of the SOD enzyme and did not affect its metal-binding site. These results revealed that flexirubin has antioxidant properties and can be a useful therapeutic compound in preventing or treating free radical-related diseases.

Box-Behnken design optimisation of a green novel nanobio-based reagent for rapid visualisation of latent fingerprints on wet, non-porous substrates.

OBJECTIVE: Optimisation of the green novel nanobio-based reagent (NBR) for rapid visualisation of groomed fingerprints on wet non-porous substrates using response surface methodology and assessment of its stability and sensitivity were attempted for forensic applications. RESULTS: Scanning electron microscopy images demonstrated successful attachments of NBR onto the constituents of fingerprints on the substrates. The highest average quality of visualised fingerprints was attained at the optimum condition (100 mg of CRL; 75 mg of acid-functionalised multi-walled carbon nanotubes; 5 h of immobilisation). The NBR produced comparable average quality of fingerprints with the commercially available small particle reagent, even after 4 weeks of storage (without any preservatives) in both chilled and sultry conditions. The NBR was sensitive enough to visualise the increasingly weaker fingerprints, particularly on glass slides. CONCLUSION: The optimised novel NBR could be the relatively greener option for visualising latent fingerprints on wet, non-porous substrates for forensic applications.

Structure and properties of lipase activated by cellulose-silica polyethersulfone membrane for production of pentyl valerate.

Herein, this study extracted nanocrystalline cellulose (NC) and silica (SiO2) from raw oil palm leaves (OPL), and employed as nanofillers in polyethersulfone (PES) to produce NC-SiO2-PES as support to immobilize Candida rugosa lipase (CRL) (NC-SiO2-PES/CRL). XRD, TGA-DTG and FTIR-ATR data affirmed that NC and SiO2 were isolated from OPL with corresponding crystallinity indices of 68 % and 70 %. A 0.02 cm membrane size with 5% (w/v) of NC-SiO2 without PVP K30 was optimal for membrane fabrication. CRL immobilized on the Glut-AP-NC-SiO2-PES membrane gave a higher conversion of pentyl valerate (PeVa) (91.3 %, p < 0.05) compared to Glut-NC-SiO2-PES (73.9 %) (p < 0.05). Characterization of the NC-SiO2-PES/CRL biocatalyst verified the presence of CRL. Hence, raw OPL is a proven good source of NC and SiO2, as reinforcement nanofillers in PES. The overall findings envisage the promising use of NC-SiO2-PES/CRL to catalyze an expedient and high yield of PeVa, alongside the suitability of NC-SiO2-PES for activating other enzymes.

Population data of 21 autosomal STR loci in Malaysian populations for human identification.

The use of 21 autosomal STR loci for human identification has been gaining popularity throughout the world. It has been indicated that the forensic statistical parameters for supporting the use of 21 STR loci varied among different populations. Hitherto, such data for the diverse Malaysian populations remain unreported, rendering doubts in the court of law about its real ability for human identification in Malaysian population. Using the GlobalFiler™ Express PCR Amplification Kit, complete DNA profiles of 21 STR loci from buccal swabs of convicted Malaysian criminal (n = 570; 190 each for Malays, Chinese, and Indians) (by the year 2016-2017) were analyzed for their allele frequencies, exact test of Hardy-Weinberg equilibrium, observed and expected heterozygosity, power of discrimination, power of exclusion, match probability, and polymorphism information content. Most of the loci were found to be in the Hardy-Weinberg equilibrium after the Bonferroni correction. Being the most informative locus, SE33 demonstrated the highest power of discrimination and power of exclusion, indicating its usefulness to discriminate individuals. In contrast, TPOX had the lowest power of discrimination and power of exclusion, as well as being the less informative genetic locus for all Malaysian population studied here. The probabilities that two individuals would share the same DNA profiles among the Malaysian Malays, Chinese, and Indians, as well as in general Malaysian population, were 1.3713 × 10-25, 2.8822 × 10-25, 7.5668 × 10-26, and 1.0385 × 10-26, respectively. The results obtained here were found comparable with similar studies reported in other populations. Hence, its robustness for forensic human identification among the Malaysian populations is, therefore, statistically supported.

Capillary electrophoresis for the analysis of antidepressant drugs: A review.

Depression is a common mental disorder that may lead to major mental health problems, and antidepressant drugs have been used as a treatment of choice to mitigate symptoms of major depressive disorders by ameliorating the chemical imbalances of neurotransmitters in brain. Since abusing antidepressant drugs such as selective serotonin reuptake inhibitors and tricyclic antidepressant drugs can cause severe adverse effects, continuous toxicological monitoring of the parent compounds as well as their metabolites using numerous analytical methods appears pertinent. Among them, capillary electrophoresis has been popularly utilized since the method has a lot of advantages viz. using small amounts of sample and solvents, ease of operation, and rapid analysis. This review paper brings a survey of more than 30 papers on capillary electrophoresis of antidepressant drugs published approximately from 1999 until 2018. It focuses on the reported capillary electrophoresis techniques and their applications and challenges for determining antidepressant drugs and their metabolites. It is organized according to the commonly used capillary zone electrophoresis method, followed by non-aqueous capillary electrophoresis and micellar electrokinetic chromatography, with details on breakthrough findings. Where available, information is given about the background electrolyte used, detector utilized, and sensitivity obtained.

Application of Box-Behnken design for ultrasound-assisted extraction and recycling preparative HPLC for isolation of anthraquinones from Cassia singueana.

INTRODUCTION: Cassia singueana Del. (Fabaceae) is a rare medicinal plant used in the traditional medicine preparations to treat various ailments. The root of C. singueana is a rich source of anthraquinones that possess anticancer, antibacterial and antifungal properties. OBJECTIVE: The objective of this study was to develop an ultrasound-assisted extraction (UAE) method for achieving a high extraction yield of anthraquinones using the response surface methodology (RSM), Box-Behnken design (BBD), and a recycling preparative high-performance liquid chromatography (HPLC) protocol for isolation of anthraquinones from C. singueana. METHODOLOGY: Optimisation of UAE was performed using the Box-Behnken experimental design. Recycling preparative HPLC was employed to isolate anthraquinones from the root extract of C. singueana. RESULTS: The BBD was well-described by a quadratic polynomial model (R2  = 0.9751). The predicted optimal UAE conditions for a high extraction yield were obtained at: extraction time 25.00 min, temperature 50°C and solvent-sample ratio of 10 mL/g. Under the predicted conditions, the experimental value (1.65 ± 0.07%) closely agreed to the predicted yield (1.64%). The obtained crude extract of C. singueana root was subsequently purified to afford eight anthraquinones. CONCLUSION: The extraction protocol described here is suitable for large-scale extraction of anthraquinones from plant extracts.

Toxic metals in Perna viridis mussel and surface seawater in Pasir Gudang coastal area, Malaysia, and its health implications.

Contamination of toxic metals in P. viridis mussels has been prevalently reported; hence, health risk assessment for consuming this aquaculture product as well as the surrounding surface seawater at its harvesting sites appears relevant. Since Kampung Pasir Puteh, Pasir Gudang is the major harvesting site in Malaysia, and because the last heavy metal assessment was done in 2009, its current status remains unclear. Herein, flame atomic absorption spectrometry and flow injection mercury/hydride system were used to determine the concentrations of Pb, Cd, Cu and total Hg in P. viridis mussels and surface seawater (January-March 2015), respectively. Significantly higher concentrations of these metals were found in P. viridis mussels (p < 0.05) than that of surface seawater samples. The concentrations for Pb (4.27-6.55 µg/g) and Cd (1.55-2.21 µg/g) in P. viridis mussels exceeded the maximum permitted proportion prescribed by the Malaysian law. The concentrations of all metals in surface seawater also violated the Malaysia Marine Water Quality Criteria and Standards. Significant (p < 0.05) and high strength of association (r = 0.787) observed between Pb concentration in P. viridis mussel with the surface seawater indicates its possible application for inferring Pb concentrations in the mussel. Since both the calculated target hazard quotient and hazard index for Pb and Cd exceeded 1, the possible detrimental health impacts on human for consuming P. viridis mussels from this rearing site cannot be ignored. Hence, promoting continuous monitoring programmes and developing efficient toxic metal removal techniques prior to entering the market are required.

Biophysical characterization of a recombinant lipase KV1 from Acinetobacter haemolyticus in relation to pH and temperature.

Spectroscopic and calorimetric methods were employed to assess the stability and the folding aspect of a novel recombinant alkaline-stable lipase KV1 from Acinetobacter haemolyticus under varying pH and temperature. Data on far ultraviolet-circular dichroism of recombinant lipase KV1 under two alkaline conditions (pH 8.0 and 12.0) at 40 °C reveal strong negative ellipticities at 208, 217, 222 nm, implying its secondary structure belonging to a α + ß class with 47.3 and 39.0% ellipticity, respectively. Results demonstrate that lipase KV1 adopts its most stable conformation at pH 8.0 and 40 °C. Conversely, the protein assumes a random coil structure at pH 4.0 and 80 °C, evident from a strong negative peak at ∼ 200 nm. This blue shift suggests a general decline in enzyme activity in conjunction with the partially or fully unfolded state that invariably exposed more hydrophobic surfaces of the lipase protein. The maximum emission at ∼335 nm for pH 8.0 and 40 °C indicates the adoption of a favorable protein conformation with a high number of buried tryptophan residues, reducing solvent exposure. Appearance of an intense Amide I absorption band at pH 8.0 corroborates an intact secondary structure. A lower enthalpy value for pH 4.0 over pH 8.0 and 12.0 in the differential scanning calorimetric data corroborates the stability of the lipase at alkaline conditions, while a low Km (0.68 ±â€¯0.03 mM) for tributyrin verifies the high affinity of lipase KV1 for the substrate. The data, herein offer useful insights into future structure-based tunable catalytic activity of lipase KV1.

Assessments on the catalytic and kinetic properties of beta-glucosidase isolated from a highly efficient antagonistic fungus Trichoderma harzianum / Avaliações das propriedades catalíticas e cinéticas da beta-glucosidase isoladas de um fungo antagonísta altamente eficiente Trichoderma harzianum

Due to the toxicity and inefficiency of chemical fungicides to control infestation of Macrophomina phaseolina (Tassi) Goid which causes charcoal rot in plants, a biotechnological approach using - glucosidase (EC.3.2.1) as the alternative bioactive ingredient in fungicide is hereby, proposed. The extracellular enzyme was isolated from a highly efficient fungal antagonist, Trichoderma harzianum T12. The highly similar molecular masses obtained using SDS-PAGE (96 kDa) and MALDI-TOF mass spectrometry (98.3 kDa) affirmed that the -glucosidase was purified to homogeneity. Consequently, optimum catalytic parameters that rendered the highest enzyme activity were found to be: 45°C, pH 7, inoculum size of 10 % (w/v), supplementation with metal ions Zn2+ and Mn2+ ions, and Tween 80. Addition of wheat bran and (NH4)2SO4 as carbon and nitrogen sources also improved enzyme activity. BLASTn showed the sequence of -glucosidase T12 was highly identical to other -glucosidases viz. T. harzianum strain IOC-3844 (99%), T. gamsii and T. virens bgl1 (86 %) as well as T. reesei strain SJVTR and T. viride strain AS 3.3711 (84 %). Kinetic assessment showed that -glucosidase T12 catalyzes hydrolytic activity is characterized by a Km of 0.79 mM and Vmax of 8.45 mM min-1 mg-1 protein, with a corresponding kcat of 10.69 s-1.

Devido à toxicidade e ineficiência dos fungicidas químicos para controlar a infestação de Macrophomina phaseolina (Tassi) Goid que causa o apodrecimento das plantas, uma abordagem biotecnológica usando - glicosidase (EC.3.2.1) como o ingrediente bioativo alternativo do fungicida é por este meio, proposto. A enzima extracelular foi isolada de um antagonista fúngico altamente eficiente, o Trichoderma harzianum T12. As massas moleculares altamente similares obtidas usando SDS-PAGE (96 kDa) e espectrometria de massa MALDI-TOF (98,3 kDa) afirmaram que a -glicosidase foi purificada até a homogeneidade. Consequentemente, os parâmetros catalíticos ótimos que apresentaram a maior atividade enzimática foram: 45°C, pH 7, tamanho do inóculo de 10% (p / v), suplementação com íons de metais Zn2+ e Mn2+, e Tween 80. Adição de farelo de trigo e (NH4) 2SO4 como fontes de carbono e nitrogênio também melhoraram a atividade enzimática. O BLASTn mostrou que a sequência da -glicosidase T12 era altamente idêntica a outras -glicosidase viz. A estirpe T. harzianum IOC-3844 (99%), T. gamsii e T. virens bgl1 (86%) assim como a estirpe T. reesei SJVTR e a estirpe T. viride AS 3.3711 (84%). A avaliação cinética mostrou que -glicosidase T12 catalisa a actividade hidrolítica caracterizada por um Km de 0,79 mM e Vmax de 8,45 mM min-1 mg-1 de proteína, com um correspondente kcat de 10,69 s-1.

Insight into the Rhizomucor miehei lipase supported on chitosan-chitin nanowhiskers assisted esterification of eugenol to eugenyl benzoate.

To overcome drawbacks in the conventional chemical route to synthesize eugenyl benzoate, immobilized Rhizomucor miehei lipase (RML) as the biocatalyst was proposed. The RML conjugated to a hybrid support consisting of biopolymers, chitosan (CS) and chitin nanowhiskers (CNWs). 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDAC) was used as the crosslinker to bind the lipase. Immobilization of RML was the highest on crosslinked CS/CNWs which gave a protein loading of ∼8.12 mg/g, corresponding to specific and residual activity of 537 U/g and 137%, respectively. Fourier transform infrared spectroscopy, thermogravimetric analysis-differential thermogravimetry, field emission scanning electron and atomic force microscopy of RML-CS/CNWs revealed that RML was successfully attached to the surface of crosslinked CS/CNWs. Under an optimized condition, the highest yield of eugenyl benzoate (56.3%) was attained after 5 h using 3 mg/mL of RML-CS/CNWs with molar ratio of eugenol: benzoic acid of 3:1, as compared to only 47.3% for the free RML. Analyses of FTIR and NMR on purified eugenyl benzoate affirmed that the ester was successfully produced in the enzymatic esterification. Therefore, the use of the RML-CS/CNWs biocatalysts appears promising to afford good yields of eugenyl benzoate within a relatively shorter reaction time.