Enzyme Source Research Articles

Discovery of novel carbohydrate degrading enzymes from soda lakes through functional metagenomics.

Extremophiles provide a one-of-a-kind source of enzymes with properties that allow them to endure the rigorous industrial conversion of lignocellulose biomass into fermentable sugars. However, the fact that most of these organisms fail to grow under typical culture conditions limits the accessibility to these enzymes. In this study, we employed a functional metagenomics approach to identify carbohydrate-degrading enzymes from Ethiopian soda lakes, which are extreme environments harboring a high microbial diversity. Out of 21,000 clones screened for the five carbohydrate hydrolyzing enzymes, 408 clones were found positive. Cellulase and amylase, gave high hit ratio of 1:75 and 1:280, respectively. A total of 378 genes involved in the degradation of complex carbohydrates were identified by combining high-throughput sequencing of 22 selected clones and bioinformatics analysis using a customized workflow. Around 41% of the annotated genes belonged to the Glycoside Hydrolases (GH). Multiple GHs were identified, indicating the potential to discover novel CAZymes useful for the enzymatic degradation of lignocellulose biomass from the Ethiopian soda Lakes. More than 73% of the annotated GH genes were linked to bacterial origins, with Halomonas as the most likely source. Biochemical characterization of the three enzymes from the selected clones (amylase, cellulase, and pectinase) showed that they are active in elevated temperatures, high pH, and high salt concentrations. These properties strongly indicate that the evaluated enzymes have the potential to be used for applications in various industrial processes, particularly in biorefinery for lignocellulose biomass conversion.

Cytobacillus pseudoceanisediminis sp. nov., A Novel Facultative Methylotrophic Bacterium with High Heavy Metal Resistance Isolated from the Deep Underground Saline Spring

In this study, we present the characterization of the BNO1T bacterial strain isolated from the deep subsurface saline spring at the Baksan Neutrino Observatory INR RAS (Kabardino-Balkaria, Russia). The complete genome sequence of the strain BNO1T is 5,347,902bp, with a GC content 41 and 49%. The cell wall peptidoglycan contains meso-diaminopimelic acid. The major isoprenoid quinone is MK-7 and the polar lipids are diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The major fatty acids are anteiso-C15:0 (23.34%), iso-C15:0 (20.10%), C16:0 (11.96%), iso-C16:0 (10.88%), and anteiso-C17:0 (10.79%). The 16S rRNA gene sequence clearly demarcated the strain as belonging to Cytobacillus genera. Based on the phylogenetic analysis, ANI (average nucleotide identity) and dDDH (digital DNA-DNA hybridization) assessments we propose to assign the strain BNO1T and other related strains to new species and to name it Cytobacillus pseudoceanisediminis sp. nov. (The values of ANI and dDDH between BNO1T and Cytobacillus oceanisediminis CGMCC 1.10115T are 80.65% and 24.7%, respectively; values of ANI and dDDH between BNO1T and Cytobacillus firmus NCTC 10335T are 89% and 38%, respectively). Genomic analysis of strain BNO1T revealed pathways for C1 compounds oxidation and two pathways for C1 compounds assimilation: serine and ribulose monophosphate pathways. In addition, strain BNO1T contains a plasmid (342,541bp) coding multiple genes involved in heavy metal ion balance. Moreover, heavy metal toxicity testing confirmed the high potential of the strain BNO1T as a source of metal resistance genes and enzymes. The type strain is BNO1T (= BIM B-1921T = VKM B-3664T).

How value addition by utilization of tilapia processing by‐products can improve human nutrition and livelihood

AbstractAquatic foods, particularly fish, are recognized as a unique source of essential fatty acids, micronutrients and protein many diets lack, especially in poor and vulnerable communities. Tilapia (Oreochromis sp.) fillets typically represent 30%–33% of the fish, leaving around 70% of the fish unused for human consumption. These nutrient‐rich by‐products can be converted into food and other products with medical, pharmaceutical and packaging applications. Heads and backbones of processed tilapias, and undersized tilapia can be used in the development or fortification of food products such as fish cakes, sausages and bread. Tilapia skin can be processed into leather for clothing and leather artefacts. Gelatin from fish skin can be developed into edible films and coating while collagen from fish scales and bones has good application in the cosmetic and pharmaceutical fields. The viscera can be converted into biodiesel or silage and hydrolysates, which are good sources of peptides and enzymes. To ensure 100% utilization, any remaining parts of the fish not used for food, can be transformed into products for animal consumption or for fertilizer. Thus, the conversion of by‐products from tilapia processing into value‐added products can contribute to improve human nutrition and better livelihood opportunities. However, adopting new technologies in value addition will require additional operational costs for acquiring new equipment and skills, a proven market demand for the products and an enabling policy environment.

Giant Viruses as a Source of Novel Enzymes for Biotechnological Application.

The global demand for industrial enzymes has been increasing in recent years, and the search for new sources of these biological products is intense, especially in microorganisms. Most known viruses have limited genetic machinery and, thus, have been overlooked by the enzyme industry for years. However, a peculiar group of viruses breaks this paradigm. Giant viruses of the phylum Nucleocytoviricota infect protists (i.e., algae and amoebae) and have complex genomes, reaching up to 2.7 Mb in length and encoding hundreds of genes. Different giant viruses have robust metabolic machinery, especially those in the Phycodnaviridae and Mimiviridae families. In this review, we present some peculiarities of giant viruses that infect protists and discuss why they should be seen as an outstanding source of new enzymes. We revisited the genomes of representatives of different groups of giant viruses and put together information about their enzymatic machinery, highlighting several genes to be explored in biotechnology involved in carbohydrate metabolism, DNA replication, and RNA processing, among others. Finally, we present additional evidence based on structural biology using chitinase as a model to reinforce the role of giant viruses as a source of novel enzymes for biotechnological application.

A molecular approach in DRUG DEVELOPMENT for the management of cognitive dysfunction in Alzheimer’s Disease.

AbstractBackgroundCognitive decline is budding as one of the greatest health threats in the current scenario as it results in conditions like impaired attention, learning, memory, and problem solving incapability in the patient of Alzheimer’s disease. Neuroinflammation, neurodegradation and oxidative stress can lead to cognitive decline and neuronal loss. Currently, only four AChE inhibitors (tacrine, rivastigmine, donepezil and galantamine) have been approved by the FDA for the symptomatic treatment of AD. However, these acetylcholinesterase inhibitors are not devoid of side effects and have lesser CNS permeability. This instigated further development in the fields of AChEIs and antioxidants for cognitive decline as investigations in these fields seems promising and encouraging. A series of novel polyamino‐substituted‐1,4‐benzoquinone molecules were designed and synthesized against the target AChE and evaluated for their in vitro, in vivo, and ex vivo AChE inhibitory activity and antioxidant potential for the development of novel potent molecules for the management of cognitive decline.MethodSeries of novel amino‐substituted‐1,4‐benzoquinone derivatives have been designed and docked with the binding pocket of the enzyme AChE. These molecules were synthesized and evaluated for their selective in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential, and for antioxidant potential using DPPH and hydrogen peroxide radical scavenging protocols. Further these compounds have been evaluated against behavioral alterations using step down passive avoidance and escape learning protocol with reference to the standard donepezil. Subsequently, compounds were further subjected for their ex vivo AChE inhibition using mice brain homogenate as the source of enzyme. Biochemical estimation of markers of oxidative stress (lipid peroxidation, superoxide dismutase, glutathione and catalase) has also been carried out to determine the role of the synthesized molecules on the scopolamine induced oxidative damage.ResultOur outcomes depicted that the anti‐amnesic effect of the synthesized conjugates on scopolamine‐induced memory impairment may be related to the mediation of cholinergic system and their effective antioxidant activity.ConclusionThe results obtained from pharmacological studies were found to be appreciable and provided promising leads which can be further explored structurally and pharmacologically, presenting a favorable scenario for the development of selective AChE inhibitors for the management of cognitive decline.

Vicagrel is hydrolyzed by Raf kinase inhibitor protein in human intestine.

As an analog of clopidogrel and prasugrel, vicagrel is completely hydrolyzed to intermediate thiolactone metabolite 2-oxo-clopidogrel (also the precursor of active thiol metabolite H4) in human intestine, predominantly by AADAC and CES2; however, other unknown vicagrel hydrolases remain to be identified. In this study, recombinant human Raf kinase inhibitor protein (rhRKIP) and pooled human intestinal S9 (HIS9) fractions and microsome (HIM) preparations were used as the different enzyme sources; prasugrel as a probe drug for RKIP (a positive control), vicagrel as a substrate drug of interest, and the rate of the formation of thiolactone metabolites 2-oxo-clopidogrel and R95913 as metrics of hydrolase activity examined, respectively. In addition, an IC50 value of inhibition of rhRKIP-catalyzed vicagrel hydrolysis by locostatin was measured, and five classical esterase inhibitors with distinct esterase selectivity were used to dissect the involvement of multiple hydrolases in vicagrel hydrolysis. The results showed that rhRKIP hydrolyzed vicagrel in vitro, with the values of Km , Vmax , and CLint measured as 20.04±1.99μM, 434.60±12.46nM/min/mg protein, and 21.69±0.28ml/min/mg protein, respectively, and that an IC50 value of locostatin was estimated as 1.24±0.04mM for rhRKIP. In addition to locostatin, eserine and vinblastine strongly suppressed vicagrel hydrolysis in HIM. It is concluded that RKIP can catalyze the hydrolysis of vicagrel in the human intestine, and that vicagrel can be hydrolyzed by multiple hydrolases, such as RKIP, AADAC, and CES2, concomitantly.

Safety evaluation of the food enzyme phytepsin from Cynara cardunculus L.

The food enzyme phytepsin (EC 3.4.23.40) is extracted from the pistils of the cardoon Cynara cardunculus L. by ABIASA. It is intended to be used in milk processing for cheese production. As no concerns arose from the source of the food enzyme, from its manufacture, and based on the history of safe use and consumption, the Panelconsidered that toxicological data and the estimation of dietary exposure were not required. The Panelconsidered that allergic reactions to this phytepsin cannot be excluded in individuals allergic to this plant. However, the likelihood of allergic reactions to the phytepsin from C. cardunculus L. is expected not to exceed the likelihood of allergic reactions to cardoon. As the prevalence of allergic reactions to cardoon is low, also the likelihood of such reaction to occur to the food enzyme is low. Based on the data provided, the Panelconcluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme rennet containing chymosin and pepsin A from the abomasum of suckling goats, lambs and calves.

The food enzyme containing chymosin (EC 3.4.23.4) and pepsin A (EC 3.4.23.1) is prepared from the abomasum of suckling goats, lambs and calves by Laboratoires Abia. The food enzyme is intended to be used in milk processing for cheese production. As no concerns arise from the animal source of the food enzyme or from its manufacture, and based on the history of safe use and consumption, the Panelconsidered that toxicological data and the estimation of dietary exposure were not required. On the basis of literature data, the Panelconsidered that, under the intended conditions of use, the risk of allergic reactions by dietary exposure could not be excluded, but the likelihood for this to occur was considered low. Based on the data provided, the Panelconcluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme phytepsin from Cynara cardunculus L.

The food enzyme phytepsin (EC 3.4.23.40) is extracted from the pistils of the cardoon (Cynara cardunculus L.) by seven manufacturers represented by the Regulation Council of Protected Designation of Origin Torta del Casar. It is intended to be used in milk processing for cheese production. As no concerns arose from the source of the food enzyme, from its manufacture, and based on the history of safe use and consumption, the Panelconsidered that toxicological data and the estimation of dietary exposure were not required. A search for similarity of the amino acid sequences of the food enzyme to known allergens was made and no matches were found. The Panelconsidered that allergic reactions to this phytepsin cannot be excluded in individuals allergic to this plant. However, the likelihood of allergic reactions to the phytepsin from C. cardunculus L. is expected not to exceed the likelihood of allergic reactions to cardoon. As the prevalence of allergic reactions to cardoon is low, also the likelihood of such reaction to occur to the food enzyme is low. Based on the data provided, the Panelconcluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme phytepsin from Cynara cardunculus L.

The food enzyme phytepsin (EC 3.4.23.40) is extracted from the pistils of cardoon (Cynara cardunculus L.) by QUALIFICA/oriGIn PORTUGAL. It is intended to be used in milk processing for cheese production. As no concerns arose from the source of the food enzyme, from its manufacture, and based on the history of safe use and consumption, the Panelconsidered that toxicological data and the estimation of dietary exposure were not required. The Panelconsidered that allergic reactions to this phytepsin cannot be excluded in individuals allergic to this plant. However, the likelihood of allergic reactions to the phytepsin from C. cardunculus L. is expected not to exceed the likelihood of allergic reactions to cardoon. As the prevalence of allergic reactions to cardoon is low, also the likelihood of such reaction to occur to the food enzyme is low. Based on the data provided, the Panelconcluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Enzyme activities in the spent mushroom substrate from Pleurotus ostreatus

Spent mushroom substrate (SMS) from Pleurotus ostreatus is residue of mushroom cultivation that is known to have lignocellulolytic enzyme activity in it. Enzyme activities provides information on evidence of fungi converting complex substrates to simple ones as nutrients for them. In this study, the enzyme was found cellulase, lignin peroxidase, and protease. The samples used consisted of three samples of SMS were collected from Padang Panjang (sample 1), Padang (sample 2), Payakumbuh (sample 3). Research was conducted to determine and compare the activity of cellulase, protease, and lignin peroxidase enzymes were evaluated as potential source of enzyme and also to determine the levels of reducing sugar, ph, and C/N ratio. Maximum activities in the SMS were 0.179 U/g cellulase, 3584.229 U/g LiP, and 1400 U/g. The value range 16,459 mg/ml to 19,845 mg/ml of reducing sugar, 5.78 to 8.08 of pH and 24.053% to 81.345% of C/N ratio. The result reveal that SMS from P. ostreatus was a good and could be a potential source of enzymes for alternative in the circular economy concept.

Study on in vitro NR biosynthesis by rapid quantitative determination of substrate depletion

A convenient and nonradioactive method for quantifying in vitro NR biosynthesis is presented that is based upon the quantitation of substrate depletion by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). NR oligomers could be in vitro biosynthesized with the enzyme source from Hevea brasiliensis (Hevea) or Taraxacum kok-saghyz (TKS) by exogenous monomers (IPP) and initiators (FPP). The IPP incorporation rate and FPP consumption rate were 62.24% and 51.14% respectively when the washed rubber particles (WRP) of Hevea was the enzyme source. The IPP incorporation rate and the FPP consumption rate were 74.49% and 95.90% respectively when the sediment bottom fraction (BF) of Hevea was the enzyme source. The in vitro NR biosynthesis can be divided into two stages:(1) the initiation reaction of FPP, which occurs more in BF, and (2) the growth reaction of IPP, which occurs more in WRP. In addition, the IPP incorporation and FPP consumption rates were 59.39% and 34.15% respectively when the BF of TKS was selected as an enzyme source.

Activity-Based Screening of Soil Samples from Nyingchi, Tibet, for Amylase-Producing Bacteria and Other Multifunctional Enzyme Capacities.

Despite the interest in Tibetan soil as a promising source of functional enzymes with potential biotechnological applications, few studies have considered the screening and identification of amylase producing bacteria from Tibetan soil. Amylase has many applications in the food and feed industries, textile and biofuel production, and biomedical engineering. The area of amylase with specific properties is attracting growing attention because of its better application to various industrial conditions. This study aims to screen and identify amylase-producing strains from soil samples collected in Nyingchi, Tibet, and then explore whether the bacterial isolates are superior for unique enzymes. In this paper, a total of 127 amylase producing bacteria were isolated by activity-based screening of six Tibetan soil samples. The 16S rRNA gene survey then identified four major phyla, namely, firmicutes, bacteroidetes, proteobacteria, and actinobacteria, which were differentiated into twelve genera with a dominance of Bacillus (67.72%), followed by Pseudomonas (8.66%). Microbial diversity analysis revealed that the amylase-producing bacterial community of the Kadinggou forest soil sample showed the best variety (the Simpson index was 0.69 and the Shannon index was 0.85). The amylase activity assay of the bacterial isolates showed a mean of 0.66 U/mL at 28°C and pH 5.2. Based on the effect of temperatures and pHs on amylase activity, several bacterial isolates can produce thermophilic (50°C), psychrophilic (10°C), acidophilic (pH 4.2), and alkaliphilic (pH 10.2) amylases. Furthermore, four bacterial isolates were screened for amylase, protease, and esterase activities, which indicated multifunctional enzyme capacities. The present study is expected to contribute to our understanding of Tibetan microbial resources and their potential for scientific research and industrial applications.

Guts Bacterial Communities of Porcellio dilatatus: Symbionts Predominance, Functional Significance and Putative Biotechnological Potential.

Terrestrial isopods are effective herbivorous scavengers with an important ecological role in organic matter cycling. Their guts are considered to be a natural enrichment environment for lignocellulosic biomass (LCB)-degrading bacteria. The main goal of this work was to assess the structural diversity of Porcellio dilatatus gut bacterial communities using NGS technologies, and to predict their functional potential using PICRUSt2 software. Pseudomonadota, Actinomycetota, Bacillota, Cyanobacteria, Mycoplasmatota, Bacteroidota, Candidatus Patescibacteria and Chloroflexota were the most abundant phyla found in P. dilatatus gut bacterial communities. At a family level, we identified the presence of eleven common bacterial families. Functionally, the P. dilatatus gut bacterial communities exhibited enrichment in KEGG pathways related to the functional module of metabolism. With the predicted functional profile of P. dilatatus metagenomes, it was possible to envision putative symbiotic relationships between P. dilatatus gut bacterial communities and their hosts. It was also possible to foresee the presence of a well-adapted bacterial community responsible for nutrient uptake for the host and for maintaining host homeostasis. Genes encoding LCB-degrading enzymes were also predicted in all samples. Therefore, the P. dilatatus digestive tract may be considered a potential source of LCB-degrading enzymes that is not to be neglected.

Penicillium polonicum a new isolate obtained from Cerrado soil as a source of carbohydrate-active enzymes produced in response to sugarcane bagasse.

The online version contains supplementary material available at 10.1007/s13205-022-03405-x.

Inclusion of partly purified protease from Abrus precatorius Linn in Ca-alginate gel beads

Abrus precatorius is an edible endemic plant in Cameroon. In the northern regions of Cameroon, the leaves of this plant are used as traditional medications, for the liquefaction of wort obtained after mashing of sorghum or millets for processing the local fermented beer called bili-bili, and to sweeten gruels made from red millet. Abrus precatorius has also being explored as a potential source of proteolytic enzymes. In this work, a partially purified protease from the leaves and stems of the plant was immobilized in a calcium alginate gel beads and the protease activity (PA), investigated using a central composite design plan under the conditions: alginate content (1–5%) (w/v), enzyme/alginate ratio (10–30%) (v/v), and CaCl2 concentration (100–400 Mmol/L). Results showed that the optimum activity was obtained for an alginate content of 1% (p/v), an enzyme/alginate ratio of 10% (v/v) and a CaCl2 concentration of 400 mmol/L. At the optimum, kinetic parameters of the immobilized enzyme (KM: 6.83 mg mL−1; Vmax: 46.95 g.L−1. min−1) were comparable to those of free enzyme (KM: 1.26 mg mL−1; Vmax: 153.85 g.L−1. min−1). The beads have been preserved at room temperature and reused for four days before loosing 88% of its activity. This indicates that the protease activity of the leaves and stems of A. precatorius can be immobilized in calcium alginate beads and preserve four days at ambient temperature.

Diverse virus-encoded CRISPR-Cas systems include streamlined genome editors

CRISPR-Cas systems are host-encoded pathways that protect microbes from viral infection using an adaptive RNA-guided mechanism. Using genome-resolved metagenomics, we find that CRISPR systems are also encoded in diverse bacteriophages, where they occur as divergent and hypercompact anti-viral systems. Bacteriophage-encoded CRISPR systems belong to all six known CRISPR-Cas types, though some lack crucial components, suggesting alternate functional roles or host complementation. We describe multiple new Cas9-like proteins and 44 families related to type V CRISPR-Cas systems, including the Casλ RNA-guided nuclease family. Among the most divergent of the new enzymes identified, Casλ recognizes double-stranded DNA using a uniquely structured CRISPR RNA (crRNA). The Casλ-RNA-DNA structure determined by cryoelectron microscopy reveals a compact bilobed architecture capable of inducing genome editing in mammalian, Arabidopsis, and hexaploid wheat cells. These findings reveal a new source of CRISPR-Cas enzymes in phages and highlight their value as genome editors in plant and human cells.

In vitro evaluation of efficacy of nonstarch polysaccharides enzymes on wheat by simulating the avian digestive tract.

In this study, the efficacy of different nonstarch polysaccharide (NSP) enzyme sources on wheat ingredients and wheat basal diets in vitro were evaluated by simulating the avian digestive tract. In Exp. 1, pH level was increased from 2.0 to 8.0 by simulating the avian digestive tract. The relative enzyme activities of xylanase A, B, and C and β-glucanase X at pH 3.0-3.5 were higher (P < 0.05) than those at pH 2.0 or 7.0-8.0. The optimal pH levels of 3.5 and 7.0 were screened by simulating the proventriculus and small intestine, respectively to evaluate the efficacy of NSP enzyme on wheat sources. In Exp. 2, wheat 1 contained the highest content of NSP fractions and the lowest digestibility in vitro dry matter (IVDMD) and energy (IVED) in wheat samples. Therefore, wheat 1 was selected for hydrolysis research under different NSP enzyme sources and levels (1,500, 4,500, 13,500, 40,500, 121,500 U xylanase/kg and 250, 500, 1,000, 2,000, 4,000 U β-glucanase/kg) in vitro. The hydrolysis of wheat on the basis of the released reducing sugar content was determined by xylanase sources A > B > C (P < 0.05) and β-glucanase sources of X > Y (P < 0.05). On the basis of the hydrolysis, the optimum dose of xylanase A and β-glucanase X were 40,500 U/kg and 2,000 U/kg, respectively. Subsequently, the completely randomized designs involving 2 NSP enzymes treatments × 2 endogenous digestive enzymes treatments (Exp. 3), as well as 2 wheat basal diets × 2 NSP enzymes treatments (Exp. 4) were used to evaluate the efficacy of NSP enzymes on dietary nutrient digestibility. The addition of NSP enzymes (40,500 U xylanase A/kg and 2,000 U β-glucanase X/kg) increased the IVDMD and IVED of wheat 1 without endogenous enzymes (P < 0.05), while the IVDMD and IVED of wheat 1 with endogenous enzyme were only slightly increased (P > 0.05). The addition of NSP enzymes could increase the IVDMD and IVED of corn-wheat-soybean meal diet (P < 0.05), but had no effect on those of wheat-cottonseed meal rapeseed meal diet (P > 0.05). In conclusion, xylanase and β-glucanase additions could effectively eliminate the adverse effects on wheat and wheat basal diets at the optimal pH levels of 3.5 and 7.0 by simulating the proventriculus and small intestine parts, respectively. The efficacy of NSP enzymes was influenced by the enzyme sources, dietary type, and the interaction of endogenous enzymes.

Development of Enzyme-Based Cosmeceuticals: Studies on the Proteolytic Activity of Arthrospira platensis and Its Efficient Incorporation in a Hydrogel Formulation

Microalgae are a valuable source of enzymes and active ingredients due to their biochemical variability, health-beneficial properties, lower production cost and viability on an industrial scale. In addition, the growing demand for sustainable products constitutes microalgae as a viable resource for the development of a range of innovative products. In the present work, the proteolytic activity of Arthrospira platensis lysate was assessed and characterized using kinetics analysis and zymography employing different substrates, pH values and divalent ions. The results suggest the presence of two main proteolytic enzymes in the lysate. In addition, a rapid and easy purification protocol of the proteolytic activity, under mild conditions, was developed using a polyethyleneglycol (PEG)/phosphate aqueous two-phase system (ATPS). The proteolytic activity of A. platensis lysate was used to develop a hydrogel formulation as an enzyme-based cosmeceutical, with potential application as a topical exfoliating agent. The incorporation of the A. platensis extract in the developed hydrogel formulation significantly improved its operational stability over time, which is a significant advantage in enzyme-based product development.

SCREENING OF ACTINOMYCETES FROM Cystoseira barbata (Stackhouse) C. Agardh COMPOST FOR THEIR ENZYME AND ANTIBACTERIAL ACTIVITIES

Bacterial secondary metabolites play an essential role in biotechnological and biomedical applications. Actinomycetes are important bacterial sources of antibiotics and enzymes. Most of the antimicrobials known today have been isolated from actinomycetes, especially from the genus Streptomyces. In this study, actinomycete isolation was performed from Cystoseira barbata (Stackhouse) C. Agardh compost, collected from the Black Sea coast, by serial dilution method. A total of 73 actinomycetes isolates (BSC) were obtained from the compost samples. The ability of the isolates to produce different extracellular enzymes was investigated qualitatively. It was determined that 68.5% of the isolates have amylase, 100% cellulase, 47.9% chitinase, 94.5% pectinase, 98.6% protease and 96.3% lipase/esterase activity. Antibacterial activities of the isolates were investigated primarily using cross-streak method. Isolates showed high antibacterial activities, with 98.6 and 84.9 % against Staphylococcus aureus Rosenbach and Enterococcus faecalis (Andrewes &amp;amp; Horder) Schleifer &amp;amp; Kilpper-Bäl, respectively. Three out of six isolates (BSC-13, BSC-17, BSC-37, BSC-38, BSC-45, BSC-49) with high antibacterial activity, were screened secondarily for their antibacterial activities using double-layer method. At day 7, BSC-37 isolate showed a high inhibition (57 mm) against S. aureus. Furthermore, these six isolates were identified according to their morphological and physiological characteristics and 16S rDNA sequence analysis. 16S rDNA sequence analysis showed that the isolates with high antibacterial activity belong to Streptomyces genus. Results indicated that these isolates have great potential and may serve as a good source for the studies on bioactive natural products.