Biomanufacturing process for the production of bacteriocins from Bacillaceae family

Members of Bacillaceae family are of major interest in medical industry due to vast antimicrobial peptides they produce as therapeutic agents. For decades, synthetic and natural occurring antibiotics have been used to treat infectious diseases, but heavy dependence on these drugs has led to significant drawbacks which propel continuous development of new antibiotics generation. Recent findings have shown several bacteriocins of Bacillaceae as promising alternatives to the conventional drugs to combat the emergence of new drug-resistant pathogens. In this present review, Bacillaceae bacteriocins’ classification such as lantibiotics and thiazole/oxazole-modified microcins as well as their biochemical characterization such as sensitivity to enzymes, temperature, pH and chemicals are described. This article enlightens on the medical application of several Bacillaceae bacteriocins emphasizing those that underwent and on-going preclinical trials. This review also discusses the development of Bacillaceae bacteriocins production, focusing strains selection and fermentation factors such as inocula size, medium (carbon, nitrogen, minerals sources), temperature, pH, agitation and aeration rate, dissolved oxygen tension (DOT), fermentation time, inducers and mode of operation via various statistical methods for their optimization. It also highlights recent advance in the production of bioengineered and recombinant bacteriocins in bioreactors system which are rarely disclosed in literature.

Discovery of new depigmenting compounds and their efficacy to treat hyperpigmentation: Evidence from in vitro study

Human skin pigmentation is a result of constitutive and facultative pigmentation. Facultative pigmentation is frequently stimulated by UV radiation, pharmacologic drugs, and hormones whereby leads to the development of abnormal skin hyperpigmentation. To date, many state-of-art depigmenting compounds have been studied using in vitro model to treat hyperpigmentation problems for cosmetic dermatological applications; little attention has been made to compare the effectiveness of these depigmenting compounds and their mode of actions. In this present article, new and recent depigmenting compounds, their melanogenic pathway targets, and modes of action are reviewed. This article compares the effectiveness of these new depigmenting compounds to modulate several melanogenesis-regulatory enzymes and proteins such as tyrosinase (TYR), TYR-related protein-1 (TRP1), TYR-related protein-2 (TRP2), microphthalmia-associated transcription factor (MITF), extracellular signal-regulated kinase (ERK) and N-terminal kinases (JNK) and mitogen-activated protein kinase p38 (p38 MAPK). Other evidences from in vitro assays such as inhibition on melanosomal transfer, proteasomes, nitric oxide, and inflammation-induced melanogenesis are also highlighted. This article also reviews analytical techniques in different assays performed using in vitro model as well as their advantages and limitations. This article also provides an insight on recent finding and re-examination of some protocols as well as their effectiveness and reliability in the evaluation of depigmenting compounds. Evidence and support from related patents are also incorporated in this present article to give an overview on current patented technology, latest trends, and intellectual values of some depigmenting compounds and protocols, which are rarely highlighted in the literatures.

Optimization of process parameters in preparation of tocotrienol-rich red palm oil-based nanoemulsion stabilized by Tween80-Span 80 using response surface methodology

Red palm oil (RPO) is a natural source of Vitamin E (70–80% tocotrienol). It is a potent natural antioxidant that can be used in skin-care products. Its antioxidant property protects skin from inflammation and aging. In our work, a tocotrienol-rich RPO-based nanoemulsion formulation was optimized using response surface methodology (RSM) and formulated using high pressure homogenizer. Effect of the concentration of three independent variables [surfactant (5–15 wt%), co-solvent (10–30 wt%) and homogenization pressure (500–700 bar)] toward two response variables (droplet size, polydispersity index) was studied using central composite design (CCD) coupled to RSM. RSM analysis showed that the experimental data could be fitted into a second-order polynomial model and the coefficients of multiple determination (R²) is 0.9115. The optimized formulation of RPO-based nanoemulsion consisted of 6.09 wt% mixed surfactant [Tween 80/Span 80 (63:37, wt)], 20 wt% glycerol as a co-solvent via homogenization pressure (500 bar). The optimized tocotrienol-rich RPO-based nanoemulsion response values for droplet size and polydispersity index were 119.49nm and 0.286, respectively. The actual values of the formulated nanoemulsion were in good agreement with the predicted values obtained from RSM, thus the optimized compositions have the potential to be used as a nanoemulsion for cosmetic formulations.

Comparative study of stirred and fluidized tank reactor for hydroxyl-kojic acid derivatives synthesis and their biological activities

Background:

Study on the synthesis of kojic acid derivatives (KADs) in solvent-free system using scalable reactors and their biological activities is still lacking.

Methods:

In this study, two types of KADs, were synthesized using saturated-fatty acid [lauric acid (LA)] and unsaturated-fatty acid [oleic acid (OA)] in stirred tank reactor (STR) and fluidized tank reactor (FTR). The yield and biological activities of the synthesized KADs were evaluated and compared.

Results:

The highest yield of KADs (42.95%) was obtained in the synthesis using OA, with molar ratio of 1:1, enzyme loading of 5% (w/v), temperature of 70°C, using immobilized lipase N435 in STR. However, FTR may provide biocatalyst protection and reusability with reduced loss of KADs yield up to three cycles. In antioxidant assay, the hydroxyl-unsaturated-fatty acid of kojic acid (HUFA-KA) showed better activity as compared to hydroxyl-saturated-fatty acid of kojic acid (HSFA-KA) at concentrations ranging from 125 to 2000 μg/mL. In contrast, HSFA-KA showed better cytotoxicity effect against G361 melanoma cell as compared to HUFA-KA.

Conclusion:

The yield of KADs obtained in STR was higher than that obtained in FTR. HUFA-KA could be used as potential lipophilic antioxidant while HSFA-KA has the potential to be used to treat melanoma skin disorder.

A Zebrafish Embryo as an Animal Model for the Treatment of Hyperpigmentation in Cosmetic Dermatology Medicine

For years, clinical studies involving human volunteers and several known pre-clinical in vivo models (i.e., mice, guinea pigs) have demonstrated their reliability in evaluating the effectiveness of a number of depigmenting agents. Although these models have great advantages, they also suffer from several drawbacks, especially involving ethical issues regarding experimentation. At present, a new depigmenting model using zebrafish has been proposed and demonstrated. The application of this model for screening and studying the depigmenting activity of many bioactive compounds has been given great attention in genetics, medicinal chemistry and even the cosmetic industry. Depigmenting studies using this model have been recognized as noteworthy approaches to investigating the antimelanogenic activity of bioactive compounds in vivo. This article details the current knowledge of zebrafish pigmentation and its reliability as a model for the screening and development of depigmenting agents. Several methods to quantify the antimelanogenic activity of bioactive compounds in this model, such as phenotype-based screening, melanin content, tyrosinase inhibitory activity, other related proteins and transcription genes, are reviewed. Depigmenting activity of several bioactive compounds which have been reported towards this model are compared in terms of their molecular structure and possible mode of actions. This includes patented materials with regard to the application of zebrafish as a depigmenting model, in order to give an insight of its intellectual value. At the end of this article, some limitations are highlighted and several recommendations are suggested for improvement of future studies.

Kinetics and Optimization of Lipophilic Kojic Acid Derivative Synthesis in Polar Aprotic Solvent Using Lipozyme RMIM and Its Rheological Study

The synthesis of kojic acid derivative (KAD) from kojic and palmitic acid (C16:0) in the presence of immobilized lipase from Rhizomucor miehei (commercially known as Lipozyme RMIM), was studied using a shake flask system. Kojic acid is a polyfunctional heterocycles that acts as a source of nucleophile in this reaction allowing the formation of a lipophilic KAD. In this study, the source of biocatalyst, Lipozyme RMIM, was derived from the lipase of Rhizomucor miehei immobilized on weak anion exchange macro-porous Duolite ES 562 by the adsorption technique. The effects of solvents, enzyme loading, reaction temperature, and substrate molar ratio on the reaction rate were investigated. In one-factor-at-a-time (OFAT) experiments, a high reaction rate (30.6 × 10⁻³ M·min⁻¹) of KAD synthesis was recorded using acetone, enzyme loading of 1.25% (w/v), reaction time of 12 h, temperature of 50 °C and substrate molar ratio of 5:1. Thereafter, a yield of KAD synthesis was optimized via the response surface methodology (RSM) whereby the optimized molar ratio (fatty acid: kojic acid), enzyme loading, reaction temperature and reaction time were 6.74, 1.97% (w/v), 45.9 °C, and 20 h respectively, giving a high yield of KAD (64.47%). This condition was reevaluated in a 0.5 L stirred tank reactor (STR) where the agitation effects of two impellers; Rushton turbine (RT) and pitch-blade turbine (PBT), were investigated. In the STR, a very high yield of KAD synthesis (84.12%) was achieved using RT at 250 rpm, which was higher than the shake flask, thus indicating better mixing quality in STR. In a rheological study, a pseudoplastic behavior of KAD mixture was proposed for potential application in lotion formulation.

Realm of Thermoalkaline Lipases in Bioprocess Commodities

For decades, microbial lipases are notably used as biocatalysts and efficiently catalyze various processes in many important industries. Biocatalysts are less corrosive to industrial equipment and due to their substrate specificity and regioselectivity they produced less harmful waste which promotes environmental sustainability. At present, thermostable and alkaline tolerant lipases have gained enormous interest as biocatalyst due to their stability and robustness under high temperature and alkaline environment operation. Several characteristics of the thermostable and alkaline tolerant lipases are discussed. Their molecular weight and resistance towards a range of temperature, pH, metal, and surfactants are compared. Their industrial applications in biodiesel, biodetergents, biodegreasing, and other types of bioconversions are also described. This review also discusses the advance of fermentation process for thermostable and alkaline tolerant lipases production focusing on the process development in microorganism selection and strain improvement, culture medium optimization via several optimization techniques (i.e., one-factor-at-a-time, surface response methodology, and artificial neural network), and other fermentation parameters (i.e., inoculums size, temperature, pH, agitation rate, dissolved oxygen tension (DOT), and aeration rate). Two common fermentation techniques for thermostable and alkaline tolerant lipases production which are solid-state and submerged fermentation methods are compared and discussed. Recent optimization approaches using evolutionary algorithms (i.e., Genetic Algorithm, Differential Evolution, and Particle Swarm Optimization) are also highlighted in this article.