Highest Chitinase Activity Research Articles

Characterization of Plant Growth-Promoting Rhizobacteria (PGPR) From Saline Soil in Taiwan

The agricultural sector is continuously facing myriad of problems such as yield loss due to abiotic stress as well as phytopathogen infestation. There is well established evidence that the use of plant growth-promoting rhizobacteria (PGPR) would overcome those problems and in turn improve plant growth and crop yield. In this research bacteria strains were isolated from root surface and inner tissue of plants grown in highly saline soils. The characterization includes the ability to produce aminocyclopropane-1-carboxylate (ACC), siderophore, chitinase as well as their antifungal ability. Those abilities are considered the most reliable traits for promoting plant growth. A total of 32 strains were isolated and examined, with 16 surface isolates and 16 endophytes. Thirty bacteria isolates showed capability to produce ACC deaminase with a range of values around 1.8 – 29.6 µmol/mg/h. Thirty isolates were found to secrete siderophore that resulted in halo zones around 1.5 mm - 15 mm after 7 days. Moreover, the chitinase assay showed 13 isolates having the ability to degrade chitin. Interestingly, two isolates with the highest chitinase activity also showed superior ability to inhibit fungal growth. To conclude, a procedure has been demonstrated that rhizobacteria with PGPR traits can be isolated from saline soil. Furthermore, some of these PGPR candidates showed potential to not only promote plant growth but also to control fungal pathogen. This type of dual-functional stains could serve as an environmentally friendly biofertilizer and meanwhile also a biocontrol agent in sustainable agriculture.

The Potential of Peroxidases Extracted from the Spent Mushroom (Flammulina velutipes) Substrate Significantly Degrade Mycotoxin Deoxynivalenol.

Little is known about the degradability of mycotoxin deoxynivalenol (DON) by the spent mushroom substrate (SMS)-derived manganese peroxidase (MnP) and lignin peroxidase (LiP) and its potential. The present study investigated the growth inhibition of Fusarium graminearum KR1 and the degradation of DON by MnP and LiP extracted from SMS. The results from the 7-day treatment period showed that mycelium inhibition of F. graminearum KR1 by MnP and LiP were 23.7% and 74.7%, respectively. Deoxynivalenol production in the mycelium of F. graminearum KR1 was undetectable after treatment with 50 U/mL of MnP or LiP for 7 days. N-acetyl-D-glucosamine (GlcNAc) content and chitinase activity both increased in the hyphae of F. graminearum KR1 after treatment with MnP and LiP for 1, 3, and 6 h, respectively. At 12 h, only the LiP-treated group had higher chitinase activity and GlcNAc content than those of the control group (p < 0.05). However, more than 60% of DON degradabilities (0.5 mg/kg, 1 h) were observed under various pH values (2.5, 4.5, and 6.5) in both MnP (50 U/g) and LiP (50 U/g) groups, while DON degradability at 1 mg/kg was 85.5% after 50 U/g of LiP treatment for 7 h in simulated pig gastrointestinal tracts. Similarly, DON degradability at 5 mg/kg was 67.1% after LiP treatment for 4.5 h in simulated poultry gastrointestinal tracts. The present study demonstrated that SMS-extracted peroxidases, particularly LiP, could effectively degrade DON and inhibit the mycelium growth of F. graminearum KR1.

Effects of Persimmon Peel on Laying Performance, Nitrogen Availability, and Egg Quality in Laying Hens Provided with Shrimp Meal Diets.

To determine whether persimmon peel (PP) showing high chitinase activity could alleviate the detrimental dietary effects of chitin-rich shrimp meal (SM), we assessed the laying performance, nitrogen (N) balance, and egg quality of laying hens provided with SM diets containing PP. We also examined the color and antioxidant properties of egg yolk, as we anticipated these would be improved by providing SM and PP. Seventy-two laying hens (45 weeks of age) were allotted to one of the nine dietary treatments (eight hens each), namely three levels of SM (0%, 10%, and 15%)×three levels of PP (0%, 6%, and 8%), and fed with the experimental diets over a period of 6 weeks. Hen-day egg production, feed intake, egg mass, feed conversion ratio, and N balance reduced with increasing levels of SM, whereas the reductions were recovered in a dose-dependent manner in response to increasing levels of PP; however, the SM0% treatment showed that PP exerted little effects. Notably, reductions in the Haugh unit and albumen height of eggs with increasing SM levels, and recovery by provision of increasing levels of dietary PP, were observed. Yolk color was improved by SM, although PP exerted little effect, whereas the antioxidant properties of yolk were enhanced by the inclusion of both SM and PP in diets. Furthermore, eggshell strength, weight, and thickness were enhanced with increasing levels of SM, whereas dietary PP had little effect on these parameters. Thus, we suggest that PP can alleviate the negative effects of dietary SM and improve egg quality, without causing a reduction in laying performance, provided that the level of supplementary PP in diets is less than 8%. These findings accordingly indicate that PP is a promising feed constituent for laying hens fed with SM diets.

Influence of chitinase production on the antagonistic activity of Trichoderma against plant-pathogenic fungi

Aim: The present study aimed to investigate the antagonistic activity of Trichoderma strains with high chitinase production against some plant pathogenic fungi. Methodology: A total of twenty-four Trichoderma isolates were extracted from soil samples collected at different geographical locations in Egypt and Saudi Arabia. These isolates were screened for their chitinase production ability using colloidal chitin media. Six isolates with high chitinase ability were identified as T. harzianum by internal transcribed spacer (ITS) region sequencing. These strains were tested for their ability to degrade chitin into N-acetyl-β-D-glucosaminidase. Finally, the biocontrol activities of these Trichoderma strains against pathogenic fungi were tested by dual culture technique. Results: The maximum activity among the chitinolytic enzymes was 0.051 units ml-1 in Trichoderma strain ABSA19, which showed an activity comparable to the control: pure enzyme, (0.047 units ml-1). The lowest activity (0.014 units ml-1) was found in Trichoderma strain MEG2. In dual culture, Trichoderma strain ABSA19 exerted the highest antagonistic activity in addition to hyphal intertwining and degradation using scanning electron microscopy. Finally, 11 inter simple sequence repeats (ISSR) primers were used to evaluate the genetic polymorphism among Trichoderma strains, which yielded 133 bands with fragment sizes of 130-3400 bp, 47 (35.3%) of which were polymorphic. Interpretation: The current study confirms the existence of several useful Trichoderma strains with the highest chitinase activity and antagonistic activity against some pathogenic plant fungi that may have a super potential for application in biological control of plant diseases.

CHITINASE PRODUCTION BY ASPERGILLUS TERREUS FROM MARINE WASTES AND ITS EFFICACY IN ANTIFUNGAL ACTIVITY

The present investigation aims to isolate and identify chitinase producing mycoflora and the chitinase production by efficient Aspergillus terreus on different shell powder wastes substrates such as prawn, crab and molluscs at an extracellular and intracellular level and its efficacy in assessing the antifungal activity. Shell fish wastes disposed soil samples were collected and screened for chitinolytic fungi (hydrolyzing zone). The chitinase production on different substrates was assessed and the enzyme extracts were screened for antifungal activity by agar well and disc diffusion methods. Among the number of mycoflora isolated only 4 fungal strains Aspergillus terreus, A. fumigatus, A. flavus, and A. clavatus showed maximum hydrolyzing zones. A significantly highest hydrolyzing zone (clearance zone) of 20 mm (out of colony diameter of 65 mm) was obtained by Aspergillus terreus. Among the different substrates (prawn, crab and molluscs shell powders at 1% concentration), highest chitinase activity was recorded by Aspergillus terreus on prawn shell powder waste followed by crab shell powder waste at an intra and extra cellular level. The chitinase produced from prawn shell powder waste as substrates by A. terreus showed maximum zone of inhibition in both agar well (28.0 mm) and disc diffusion (24.0 mm) methods against the pathogenic fungi, A. flavus compared to positive control (Fluconazole). The chitinase produced from A. terreus might have synthesized some antifungal compounds which may be responsible for killing pathogenic fungi.

Knockout of SlNPR1 enhances tomato plants resistance against Botrytis cinerea by modulating ROS homeostasis and JA/ET signaling pathways.

Tomato is one of the most popular horticultural crops, and many commercial tomato cultivars are particularly susceptible to Botrytis cinerea. Non-expressor of pathogenesis-related gene 1 (NPR1) is a critical component of the plant defense mechanisms. However, our understanding of how SlNPR1 influences disease resistance in tomato is still limited. In this study, two independent slnpr1 mutants were used to study the role of SlNPR1 in tomato resistance against B. cinerea. Compared to (WT), slnpr1 leaves exhibited enhanced resistance against B. cinerea with smaller lesion sizes, higher activities of chitinase (CHI), β-1, 3-glucanases (GLU) and phenylalanine ammonia-lyase (PAL), and significantly increased expressions of pathogenesis-related genes (PRs). The increased activities of peroxidase (POD), ascorbate peroxidase (APX) and decreased catalase (CAT) activities collectively regulated reactive oxygen species (ROS) homeostasis in slnpr1 mutants. The integrity of the cell wall in slnpr1 mutants was maintained. Moreover, the enhanced resistance was further reflected by induction of defense genes involved in jasmonic acid (JA) and ethylene (ET) signaling pathways. Taken together, these findings revealed that knocking out SlNPR1 resulted in increased activities of defense enzymes, changes in ROS homeostasis and integrity of cell walls, and activation of JA and ET pathways, which confers resistance against B. cinerea in tomato plants.

Silicon, Clonostachys rosea, and their interaction for gray mold management in cucumber

Cucumber is one of the most profitable crops cultivated worldwide and the occurrence of gray mold, caused by Botrytis cinerea, can dramatically decrease yield and fruit quality. This study investigated the potential of using silicon (Si), Clonostachys rosea, and their interaction, to control gray mold and on the potentiation of biochemical mechanisms of host defense. The treatments used in this study were: plants not-supplied with Si and not-receiving C. rosea (Cr) in the substrate before sowing (-Si -Cr plants), plants not-supplied with Si and receiving C. rosea (-Si +Cr plants), plants supplied with Si and not-receiving C. rosea (Cr) (+Si-Cr plants), and plants supplied with Si and receiving C. rosea (+Si+Cr plants). The foliar Si concentration significantly increased by 78% for +Si-Cr plants and by 98% for +Si +Cr plants in comparison to -Si-Cr and -Si+Cr plants, respectively. Significant increases of 70 and 73% for the incubation period of gray mold occurred for -Si+Cr and +Si+Cr plants, respectively, in comparison to -Si-Cr plants. There were significant reductions of 41 and 51%, respectively, for -Si+Cr and +Si+Cr plants in comparison to -Si-Cr plants for area under gray mold progress curve. The -Si+Cr and +Si+Cr plants showed high chitinase activity at 5 and 7 days after inoculation (dai) and at 9 hai for +Si-Cr plants in comparison to -Si-Cr plants. For +Si-Cr plants at 3 and 7 dai and for +Si+Cr plants at 3 and 5 dai, β-1,3-glucanase activity was significantly higher in comparison to -Si-Cr plants. Polyphenoloxidase activity was significantly higher for +Si-Cr plants at 5 dai and for -Si+Cr plants at 7, 8, and 10 dai in comparison to -Si-Cr plants. For -Si+Cr plants at 3 and 7 dai, +Si+Cr plants at 3 and 8 dai, and +Si-Cr plants at 7 and 8 dai, peroxidase activity was significantly higher in comparison to -Si-Cr plants. This study brings new insights into the potential of applying C. rosea and Si to boost cucumber resistance against gray mold with a bright prospect to be used in cucumber production under greenhouse conditions.

Optimization of process parameters for improved chitinase activity from Thermomyces sp. by using artificial neural network and genetic algorithm

Chitinase is responsible for the breaking down of chitin to N-acetyl-glucosamine units linked through (1–4)-glycosidic bond. The chitinases find several applications in waste management and pest control. The high yield with characteristics thermal stability of chitinase is the key to their industrial application. Therefore, the present work focuses on parameter optimization for chitinase production using fungus Thermomyces lanuginosus MTCC 9331. Three different optimization approaches, namely, response surface methodology (RSM), artificial neural network (ANN) and genetic algorithm (GA) were used. The parameters under study were incubation time, pH and inoculum size. The central composite design with RSM was used for the optimization of the process parameters. Further, results were validated with GA and ANN. A multilayer feed-forward algorithm was performed for ANN, i.e., Levenberg–Marquardt, Bayesian Regularization, and Scaled Conjugate Gradient. The ANN predicted values gave higher chitinase activity, i.e., 102.24 U/L as compared to RSM-predicted values, i.e., 88.38 U/L. The predicted chitinase activity was also closer to the observed data at these levels. The validation study suggested that the highest activity of chitinase as predicted by ANN is in line with experimental analysis. The comparison of three different statistical approaches suggested that ANN gives better optimization results compared to the GA and RSM study.

Improvement in the in vitro Digestibility of Shrimp Meal by the Addition of Persimmon Peel.

The present study was conducted to analyze the chemical properties of persimmon peel (PP) and the in vitro digestibility of shrimp meal (SM) diets containing PP. Discussions whether PP can be used as a feed additive to promote digestion of SM in chickens are also included. The chemical composition and chitinase activity of dried PP was studied. SM diets containing PP were formulated according to the 4 by 6 factorial design: 4 levels of SM (0%, 10%, 15%, and 20%) × 6 levels of PP (0%, 2%, 4%, 6%, 8%, and 10%). The in vitro digestibility of dry matter (IVDMD), crude protein (IVCPD), and chitin (IVCD) was also studied. PP was rich in nitrogen-free extract (NFE, about 74%) and tannin (2.8%), and the highest chitinase activity of PP was observed at pH 4.5. Approximately 50% of chitinase activity was also observed at acidic (3.0) and alkaline (8.0) pH. Its activity was slightly affected by pepsin treatment. IVDMD increased upon addition of up to 8% PP, but decreased with an increase in the level of SM. When PP level was increased up to 6%, IVCPD in the group containing 0% SM, changed slightly; however, an increasing trend was observed in the other groups. When PP level was more than 6%, IVCPD decreased in all the groups. IVCD increased dose-dependently with increasing level of PP and decreased with increasing level of SM. In conclusion, PP was rich in NFE, had high chitinase activity, and improved all digestibility parameters, such as IVDMD, IVCPD, and IVCD, in SM diets where the PP level was under 6%. Thus, up to 6% of PP can be safely included in SM diets as a digestion promoter.

Phytophthora Antagonism of Endophytic Bacteria Isolated from Roots of Black Pepper (Piper nigrum L.)

In this study, 90 root samples were collected from 30 black pepper farms in three provinces in the Central Highlands of Vietnam. A total of 352 endophytic bacteria were isolated and their morphology described. An in vitro assay on the antifungal activity of these isolates was then conducted and 47 isolates were found to have antagonistic activity on Phytophthora fungi. The antifungal activity of the 47 isolates was evaluated in vivo by shoot assay. Among these 47 isolates, 6 were selected for further investigation. The six isolates were classified and identified by sequencing the 16S RNA gene and phylogeny. The results showed that all six endophytic bacteria belong to the following species of Bacillus genus: B. siamensis, B. amyloliquefaciens, B. velezenis, and B. methylotrophiycus. Enzymatic activity related to the antifungal activity of the six potent isolates was determined; it showed that they possessed high chitinase and protease activities. These isolates were applied for black pepper seedlings in greenhouse. The results showed three promising isolates: B. siamensis EB.CP6, B. velezensis EB.KN12, and B. methylotrophycus EB.KN13. Black pepper seedlings treated with the promising bacteria had the lowest rate of root disease (8.45–11.21%) and lower fatal rate (11.11–15.55%) compared to the control group (24.81% and 24.44%). In addition, the three promising isolates strongly affected the growth of the black pepper seedlings in greenhouse. The plant height, length of roots, and fresh biomass of the seedlings in the treated plots were higher than those in the control plots. Thus, the endophytic bacterial isolates have the potential to act as biocontrol agent for the sustainable production of black pepper.

Optimization of Agitation Rate in Bioreactor Increases Chitinase Activity ofSerratia marcescensPT6

Serratia marcescensPT6 is a Gram-negative bacteria isolated from shrimp pond sediment that capable of producing chitinase. This study aimed to observe the effect of agitation rate on growth and chitinase activity ofS. marcescensPT-6 in a bioreactor. The production of chitinase was done in 1.5 l bioreactor using colloidal chitin broth at the condition of pH 7, the temperature of 30°C, aeration of 0.04 vvm, and variation of agitation rate (200, 350, 500 rpm). Bacterial growth was measured by colonies counting in agar medium, while chitinase activity was measured by means of colorimetric every day for four days incubation. The results of ANOVA analysis show that the agitation rate had no effect on bacterial growth, but a significant effect (P&lt;0.05) was observed on chitinase activity. The highest growth and chitinase activity were obtained at 200 rpm, with the highest chitinase activity of 0.006 ± 0.001 U/ml was at day-2. This study implies that the optimized agitation rate in the bioreactor increased the chitinase activity produced byS. marcescens PT-6.

Optimization of Colloidal Chitin and Inoculum Concentration in Chitinase Production byStreptomycessp. PB2 Using Response Surface Methodology

Chitinase is an enzyme capable of catalyzing the hydrolysis of chitin. Bacteria is one of the sources for chitinase and the modification process of production are continously developed.Streptomycessp. is one of Actinomycetes group that shows high activity in hydrolyzing chitin. This study aimed to find the optimal conditions ofStreptomycessp. PB2 for producing chitinase at various colloidal chitin (0.5%, 1%, 1.5%) and inoculum (0.5%, 1%, 1.5%) concentration in the chitin broth medium using Respons Surface Methodology (RSM). The examined parameters included Total Plate Count (CFU/ml) and chitinase activity (U/ml). Chitinase activity was statistically analyzed by MiniTab 17 to obtain a mathematical model, then were validated. The mathematical model of chitinase activity was Y = -0.000075 + 0.00056 K + 0.00067 I, with the optimum colloidal chitin concentration (K) of 1.5% and inoculum concentration (I) of 1.5%. The highest chitinase activity of 0.0019 U/ml in day-2 fermentation. The validation test showed that the mathematical model had a low accuracy with the SSE value of 0.5306. This study shows that colloidal chitin and inoculum concentration are important factors to be optimized. However, further model is needed to be developed for a better estimation of process.

Evaluation of enzymatic activity and identification of potent proteolytic and chitinolytic bacteria isolated from crab shell waste

Abstract. Dliyauddin M, Ardyati T, Suharjono. 2020. Evaluation of enzymatic activity and Identification of Potent Proteolytic and Chitinolytic Bacteria Isolated from Crab Shell Waste. Biodiversitas 21: 211-218. Proteolytic and chitinolytic bacteria are needed to degrade protein-chitin fibers in crab shell waste. These bacteria are important for enhancing the degradation rate of crab shell waste in the environment. This study aims to study the enzymatic activity and identify potent proteolytic and chitinolytic bacteria based on 16S rDNA sequences. The bacteria were isolated from crab shell waste using skim milk agar and colloidal chitin agar for proteolytic and chitinolytic bacteria, respectively. The bacterial isolates were screened based on their protease and chitinase activity using casein and chitin as substrates, respectively. The selected isolates were identified based on 16S rDNA sequences similarity. A total of 20 proteolytic and 22 chitinolytic bacteria were successfully isolated from the samples. The isolate of AP9, AP5, and BP14 had a high protease activity. However, only BP14 and CK20 showed a high chitinase activity. The isolate of AP9 was identified as Bacillus subtilis, AP5, and CK20 were identified as Bacillus licheniformis, and BP14 was identified as Bacillus cereus. AP5 dan CK20 were classified as non-pathogenic isolates.

Phylogeny, chitinase activity, and pathogenicity of Beauveria, Metarhizium and Lecanicillium species against cowpea aphid, Aphis craccivora Koch

Cowpea aphid, Aphis craccivora Koch is a serious insect pest of cowpea distributed in almost all states of India and its management is essential to increase the quality and quantity of cowpea yield. This study sought to characterize the indigenous isolates of fungal entomopathogens, Beauveria bassiana, Metarhizium pingshaense, M. guizhouense, and Lecanicillium muscarium, using molecular phylogeny and evaluate their pathogenicity against A. craccivora under greenhouse conditions and compare their extracellular chitinase activity. Thirty isolates of fungal entomopathogens were collected from semi-natural and agricultural habitats. Molecular phylogeny of these isolates using partial nuclear sequences, Bloc and MzIGS3, and mitochondrial sequence, nad1, resolved four species. Screening of the isolates against A. craccivora using a single concentration of 1 × 106 conidia/ml revealed that all isolates were pathogenic, with mortality of aphids ranging from 16.67 to 100%. Bioassays of the highly pathogenic isolates of B. bassiana, M. pingshaense, and L. muscarium against A. craccivora revealed low LC50 value of L. muscarium isolate GKVK 03_11 (1.4 × 105 conidia/ml) under greenhouse conditions. Comparison of the extracellular chitinase activity of these isolates detected high chitinase activity of GKVK 03_11 isolate (0.621 U/ml). Study results suggest the biocontrol potential of indigenous L. muscarium isolate for the management of A. craccivora and the possible role of chitinase enzyme in the virulence of fungal entomopathogens.

Trichoderma brevicrassum strain TC967 with capacities of diminishing cucumber disease caused by Rhizoctonia solani and promoting plant growth

Some Trichoderma species have been used as biocontrol agents in agriculture. In order to explore additional useful natural resources, a large scale survey of Trichoderma strains from China was conducted and T. brevicrassum strain TC967 was singled out. In vitro assays indicated that it showed high chitinase activity in agar medium, inhibited growth of the plant-pathogenic fungus Rhizoctonia solani (72.14%) in dual culture, and revealed strong mycoparasitic ability through coiling and penetrating hyphae of the pathogen. In vivo assays indicated that it was able to suppress the cucumber disease caused by R. solani to a low disease index (37.5%). Hyphae of strain TC967 colonized cucumber root surface, induced the expression of pathogenesis-related protein genes PR1, PR4 and PR5. In addition, strain TC967 promoted cucumber growth. This is the first report of T. brevicrassum having biocontrol potential and promoting cucumber growth.

Antifungal Potentiality and Physiological Characterization of Trichoderma Isolates from Port Said Governorate

A TOTAL of twenty Trichoderma isolates belonging to seven species were isolated from several locations at Port Said Governorate. Physiological characteristics of these isolates and their antagonistic effect against Sclerotinia sclerotiorum, the causative agent of white mold of Phaseolus vulgaris were evaluated. Trichoderma polysporum 2 showed the highest activity of total cellulase reached up to 2.95 filter paper unit ml-1. T. harzianum 2 had the highest endoglucanase activity (5.47 IU ml-1), whereas T. polysporum 1 had the highest chitinase activity (1.01 IU ml-1). Siderophores production was assayed using FeCl3, tetrazolium, Arnow’s and spectrophotometric tests. Most of the isolates were able to produce hydroxamate and carboxylate types of siderophores. The ability of Trichoderma to produce indole acetic acid (IAA) and gibberellic acid (GA3) were also investigated. Trichoderma harzianum 2 showed the highest concentration of IAA in broth medium reached up to 13.19μg/ml, whereas T. polysporum 1 showed the highest concentration of GA3 by 586.51μg/ml. The antagonistic potentialities of Trichoderma isolates against Sclerotinia sclerotiorum were tested in vitro by using dual culture, base to base assay and the crude liquid extract effect of the isolates. Percentages of inhibition of radial growth of the pathogen by T. polysporum 1 in dual culture and crude extract methods were 45.97% and 87.78%, respectively. Also, the volatiles of T. piluliferum 2 showed a reduction of the radial growth by 66.85%. So, some Trichoderma isolates collected from Port Said soil showed high biocontrol activity against S. sclerotiorum.

Serum chitinase activity prognosticates metastasis of colorectal cancer

BackgroundThis study aimed to evaluate the value of chitinase activity in prognosticating the occurrence of metastasis in and prognosis of patients with colorectal cancer (CRC).MethodsThe chitinase activity in four different groups, namely 335 CRC patients without distant metastasis at their first visit (Group 1), 51 patients with CRC having synchronous liver metastasis (Group 2), 100 healthy age-matched controls (Group 3) and 40 patients with liver cancer (Group 4), were assayed using an enzyme-linked immunosorbent assay. The Cox proportional hazards ratio model and Kaplan–Meier curve were used to identify the association between chitinase activity and the clinical outcome of CRC patients without metastasis in the training set and testing set at their first visit. An in vitro Transwell experiment was performed to evaluate the migration of colon cancer cells.ResultsPatients with high chitinase activity had a significantly higher metastasis risk than those with low chitinase activity in the training and testing sets during follow-up, both at stage I/II and stage III. Further, multivariate analysis revealed that chitinase activity was an independent risk factor prognosticating liver metastases (P = 0.001). The combination of chitinase activity and lymph node metastasis status increased the accuracy of the prognosis of liver metastases after radical resection (P = 0.454E-011). In addition, chitinase promoted CRC cell migration in vitro.ConclusionsChitinase activity can prognosticate the occurrence of metastasis in patients with CRC. Moreover, the combination of chitinase activity and N stage increased the power of prognosticating the occurrence of metastasis. Inhibiting chitinase activity may serve as a new strategy to treat metastases of CRC.

A multispecies consortium of bacteria having plant growth promotion and antifungal activities, for the management of Fusarium wilt complex disease in potato (Solanum tuberosum L.)

Abstract Fusarium oxysporum F9 and Fusarium sp. F15 were found to be the causal organisms of wilt disease complex of potato (Solanum tuberosum L.) in Cachar region of Assam, India. Based on the biocontrol activity against the two fusaria and plant growth promoting attributes such as siderophore, IAA, HCN and chitinolytic activities, six bacterial isolates were selected. These isolates were identified as Pseudomonas aeruginosa (B4, B23, B25 and B35), Serratia marcescens (B8) and Alcaligenes feacalis (B16) based on their 16S rDNA homology. Further, BOX-PCR was used to evaluate genetic diversity among the isolates. The maximum inhibition of mycelial growth against F15 and F9, was shown by P. aeruginosa B35 (i.e. 76.15% and 85.88% respectively). All the isolates were found to produce IAA and siderophore. Three isolates, S. marcescens B8, P. aeruginosa B4, and P. aeruginosa B35 produced chitinase, and highest chitinase activity was recorded for B35 (0.70 U/ml). The genes for antibiotic synthesis such as phlD for 2,4-diacetylphloroglucinol (DAPG) was present in A. feacalis B16, while phenazine (phzF) was found to present in all four pseudomonads (B4, B23, B25 and B35), which was confirmed by thin layer chromatography analysis. The inoculation of the bacterial consortium in fusaria infested soil (F9 + F15) resulted in a 94% reduction of wilt incidence, while plant biomass was also enhanced significantly (p

Distribution of Chitinolytic Enzyme in the Organs and Molecular Cloning of a Novel Chitinase Gene from the Kidney of Marbled Rockfish &amp;lt;i&amp;gt;Sebastiscus marmoratus&amp;lt;/i&amp;gt;

Actinopterygii express two types of chitinase (acidic fish chitinase-1 (AFCase-1) and acidic fish chitinase-2 (AFCase-2)) that are active at acidic pHs and involved in digestion in the stomach. We proposed the existence of a new fish chitinase that has a non-digestive function. In this study, we used Sebastiscus marmoratus, for which characteristics and cDNA cloning of chitinase isozymes (SmChi-1, SmChi-2) in the stomach have been reported. Initially, we examined the distribution of chitinase and β-N-acetylhexosaminidase (Hex) in the body and then we tried to clone novel chitinase cDNA from the kidney. Chitinase and Hex activities were measured using pNP-(GlcNAc)n, (n = 2, 3) and pNP-GlcNAc as substrates, respectively. Total RNA was extracted from the kidney. RT-PCR was performed to obtain chitinase cDNA fragments using reverse transcriptase with an oligo dT primer. The RACE method was used to obtain sequences of the upstream and downstream regions of cDNA. The full-length chitinase cDNA was determined using PrimeSTAR® Max DNA polymerase with proofreading activity. High chitinase activity was observed in the stomach, as previously reported. In addition, relatively high activity was observed in the liver, spleen, kidney, and heart. In contrast, Hex activity was detected in all organs. This result is consistent with the report that Hex is related to body-wide metabolism. Full-length cDNA (SmChi-3) of the novel chitinase was obtained from the kidney, which contained 1440 bp open reading frames. The domain structure of SmChi-3 was assumed to be similar to those of SmChi-1 and SmChi-2. SmChi-1 and SmChi-2 have a serine and glycine-rich linker region, which is characteristic of AMCase. In contrast, SmChi-3 contained no apparent sequence in the linker region. Phylogenetic analysis revealed the existence of a new chitinase group, which was named fish chitinase-3 (FCase-3) and differed from AFCase-1 and AFCase-2.

Effect of nitrogen sources and fermentation conditions on bacillus sp. R2 chitinase production

The nutritional and environmental conditions have a great influence on chitinase production, due to the receptor-inducer system that control enzymes production.in these sense, the aim of this study was to screen several nitrogen sources and optimize the most important fermentation conditions affecting Bacillus sp. R2 chitinase production. The results of one variable at time technique (OVAT) in shake flasks, revealed that among various nitrogen sources tested 0.5% yeast extract led to maximum production. Furthermore, the highest chitinase activity was detected after 24 h incubation period at temperature of 30C, initial pH: 7.5, 2.5 to 3% NaCl concentration and under 180 rpm shaking using 2.5% (8.9 × 108 CFU/ml) as best inoculum size. These optimizations can reduce the cost of chitinase production for the large scale specially