An in vitro Study on the Adsorption, Absorption and Uptake Capacity of Zn by the Bioremediator Trichoderma atroviride

The concentrations of Zn in the sediment of a polluted river at the Serdang Industrial Area were determined. These polluted sediment samples revealed high level of Zn (219. 27 µg/g). Isolation of fungi from this polluted sediment was also carried out using Rose Bengal Agar (RBA). The isolated fungi were exposed to different concentrations of Zn (0-6000 mg/L) on Potato Dextrose Agar (PDA) to find the most tolerant isolate. Trichoderma atroviride was found to have the highest tolerance and it was studied for growth rate, Zn uptake capacity, its tolerance to Zn and also localization of Zn by using Potato Dextrose Broth (PDB) as the liquid culture medium. In the present study the results found out that the uptake capacity of T. atroviride ranged from 18.1-26.7 mg/g in liquid media at Zn concentrations from 500 to 1000 mg/L. The isolate showed 47.6-64% adsorption and 30.4¬45.1% absorption for Zn. Based on the present study, 5.7-7.4% of Zn removal was observed due to biomass washing. The high adsorption, relatively low absorption and high uptake capacity of Zn suggest that T. atroviride is a potential bioremediator of Zn. However, further studies are needed to confirm its practical use as a bioremediating agent for Zn under field conditions

Tolerance of Trichoderma Atroviride (Karst.) Isolated From Freshwater Ecosystems towards Copper and Zinc

Isolation of microfungi from sediment samples of Kuyoh River Industrial Area, Kuyoh River Residential Area and Sri Serdang Lake was done on Rose Bengal Agar (RBA). The fungi were exposed to increased concentrations of Cu2+ (5 to 600 mg/L) and Zn2+ (5 to 6000 mg/L) on Potato Dextrose Agar (PDA) to find the most tolerant isolate. The highest tolerance to both elements was shown by Trichoderma atroviride. Further studies on growth rate, uptake capacity and localization of Cu2+ and Zn2+ were made by using Potato Dextrose Broth (PDB) incorporated with 25 to 300 mg/L of Cu2+ and 500 to 1000 mg/L of Zn2+. This study found that the uptake capacity of T. atroviride for Cu2+ ranged from 0.77 to 11.20 mg/g between 25 to 300 mg/L in the liquid medium while that for Zn2+ ranged from 18.1 to 26.7 mg/g between 500 to 1000 mg/L in the liquid medium. The isolate showed that 50.3 to 85.4 % adsorption and 9.6 to 47.1 % absorption for Cu2+ and 47.6 to 64% adsorption and 30.4 to 45.1% absorption for Zn2+. Based on the present studies, 2.7 to 5 % of Cu2+ and 5.7 to 7.4 % of Zn2+removal was observed due to biomass washing. The mean levels of Cu2+ in the surface sediment of the three mentioned sites were 347.64 μg/g, 32.04 μg/g and 21.71 μg/g while the mean levels of Zn2+were 219.75 μg/g, 140.64 μg/g and 85.10 μg/g, respectively. This study suggests that T. atroviride is a potential bioremediator of Cu2+ and Zn2+. However, further studies are needed to confirm its practical use as a bioremediating agent

Adsorption and absorption of Cu in Trichoderma atroviride

Conventional methods for removing heavy metals from polluted waters, using chemical precipitation, sludge separation, chemical oxidation or reduction, and ion exchange, have been uneconomical and are weak processes. An alternative technique is the use of fungi as bioremediating agents. A strain of Trichoderma atroviride, isolated from a river passing through the metal polluted Serdang industrial area, was studied for its uptake and tolerance to Cu. This study found that the uptake capacity of T. atroviride for Cu ranged from 0.77 to 11 .20 mg/g in Potato Dextrose Broth in liquid media over the Cu concentration range of 25 to 300 mgIL. The isolate showed 50.3 to 85.4% adsorption and 9.6 to 47.1% absorption. These adsorption and absorption values are comparable to any good bioremediators for Cu found in the literature. This study suggests that T. atroviride is a potential bioremediator of Cu. However, further studies are still needed to confirm its practical use as a bioremediating agent under field conditions

Is the high Cu tolerance of Trichoderma atroviride isolated from the Cu-polluted sediment due to adaptation? an in vitro toxicological study

The tolerance of Cu by Trichoderma atroviride, a tolerant fungus isolated from the drainage surface sediment of the Serdang Industrial Area was investigated under in vitro conditions. Only this fungus species can tolerate up to 600 mg/L of Cu on solid medium Potato Dextrose Agar based on the isolation of the most tolerant fungus from the polluted sediment.Toxicity test performed on T. atroviride, showed a maximum tolerance at 300 mg/L of Cu concentration when grown in liquid medium Potato Dextrose Broth (PDB). The EC 50 value of the isolate was 287.73 mg/L of Cu concentration in PDB.The Cu concentration in the drainage surface sediment, where the T. atroviridewas isolated from, was 347.64 μg/g while the geochemical distributions of the non-resistant and resistant fractions of Cu were 99.6 and 0.4%, respectively. The sediment data indicated that the drainage had greatly received anthropogenic Cu from the nearby industries which are involved in the manufacturing of plastics and electronic products. The present findings indicate that the high Cu tolerance showed by T. atroviride could be due to the well adaptation of the fungus to the Cu polluted sediment. Therefore, T. atroviride could be a potential bioremediator of Cu pollution in the freshwater ecosystem

Trichoderma atroviride as a bioremediator of Cu pollution: an in vitro study

Isolated Trichoderma atroviride from Cu-polluted river sediment at the Serdang Industrial Area was studied under in vitro conditions to understand the mechanisms that allowed the fungi to thrive in the Cu-polluted freshwater ecosystem. From this study, adsorption was recognized as the main mechanism of Cu tolerance with 50–85% adsorption during the in vitro experiment. The uptake capacity of the isolate in liquid medium ranged from 0.8 to 11.2mg g1 in the potato dextrose broth medium with increasing Cu concentrations from 25 to 300mg L1. It was found that 2.7–5.0% of Cu was lost due to washing. The high percentage of Cu adsorption and the high uptake capacity of Cu by T.atroviride suggest that it is a potential bioremediator of Cu. However, further studies are needed to confirm its practical use as a bioremediating agent for Cu under field conditions

An in vitro study on the adsorption, absorption and uptake capacity of Zn by the bioremediator Trichoderma atroviride.

The concentrations of Zn in the sediment of a polluted river at the Serdang Industrial Area were determined. These polluted sediment samples revealed high level of Zn (219. 27 μg/g). Isolation of fungi from this polluted sediment was also carried out using Rose Bengal Agar (RBA). The isolated fungi were exposed to different concentrations of Zn (0-6000 mg/L) on Potato Dextrose Agar (PDA) to find the most tolerant isolate.Trichoderma atroviride was found to have the highest tolerance and it was studied for growth rate, Zn uptake capacity, its tolerance to Zn and also localization of Zn by using Potato Dextrose Broth (PDB) as the liquid culture medium. In the present study the results found out that the uptake capacity of T. atroviride ranged from 18.1-26.7 mg/g in liquid media at Zn concentrations from 500 to 1000 mg/L. The isolate showed 47.6-64% adsorption and 30.4-45.1% absorption for Zn. Based on the present study, 5.7-7.4% of Zn removal was observed due to biomass washing. The high adsorption, relatively low absorption and high uptake capacity of Zn suggest that T. atroviride is a potential bioremediator of Zn. However, further studies are needed to confirm its practical use as a bioremediating agent for Zn under field conditions

Distinct Subsets of Noncoding RNAs Are Strongly Associated With BMD and Fracture, Studied in Weight-Bearing and Non–Weight-Bearing Human Bone

We investigated mechanisms resulting in low bone mineral density (BMD) and susceptibility to fracture by comparing noncoding RNAs (ncRNAs) in biopsies of non–weight-bearing (NWB) iliac (n = 84) and weight bearing (WB) femoral (n = 18) postmenopausal bone across BMDs varying from normal (T-score > −1.0) to osteoporotic (T-score ≤ −2.5). Global bone ncRNA concentrations were determined by PCR and microchip analyses. Association with BMD or fracture, adjusted by age and body mass index, were calculated using linear and logistic regression and least absolute shrinkage and selection operator (Lasso) analysis. At 10% false discovery rate (FDR), 75 iliac bone ncRNAs and 94 femoral bone ncRNAs were associated with total hip BMD. Eight of the ncRNAs were common for the two sites, but five of them (miR-484, miR-328-3p, miR-27a-5p, miR-28-3p, and miR-409-3p) correlated positively to BMD in femoral bone, but negatively in iliac bone. Of predicted pathways recognized in bone metabolism, ECM-receptor interaction and prote

A Hyaluronan Hydrogel Scaffold for Culture of Human Oral Mucosal Epithelial Cells in Limbal Stem-Cell Therapy

Hyaluronan (HA), a major component of the extracellular matrix, plays a key role in cell proliferation, growth, survival, polarization and differentiation. We investigated the optimization of a HA hydrogel scaffold for culture of human oral mucosal epithelial cells (OMECs) for potential application in limbal stem cell therapy. The effect of the optimized scaffold on OMEC cell sheet morphology, cell metabolic activity and expression of genes associated with stemness, adherence and cell damage was studied. The results indicate that HA hydrogels crosslinked with polyethylene glycol diacrylate (PEGDA) failed to support OMEC attachment and growth. However, HA hydrogel scaffolds dried for three days and coated with 1 mg/mL collagen IV produced a full OMEC sheet. Cell morphology was comparable to control after three weeks culture, maintaining 76% metabolic activity. Of apoptosis-related genes, the pro-apoptotic markers CASP3 and BAX2 were upregulated and downregulated, respectively, compared to control whereas the anti-apoptotic marker BCL2 was downregulated. The expression level of stemness genes ΔNp63α and ABCG2 was significantly higher than control. Genes associated with improved scar-less wound healing (integrin-αV) and protection of the ocular surface (cadherin-1) had ~3-fold increased expression. These data suggest that our optimized HA-hydrogel scaffold could enhance culture of OMEC cell sheets for use in ocular reconstruction

Hyaluronan-Based Hydrogel Scaffolds for Limbal Stem Cell Transplantation: A Review

Hyaluronan (HA), also termed hyaluronic acid or hyaluronate, is a major component of the extracellular matrix. This non-sulfated glycosaminoglycan plays a key role in cell proliferation, growth, survival, polarization, and differentiation. The diverse biological roles of HA are linked to the combination of HA’s physicochemical properties and HA-binding proteins. These unique characteristics have encouraged the application of HA-based hydrogel scaffolds for stem cell-based therapy, a successful method in the treatment of limbal stem cell deficiency (LSCD). This condition occurs following direct damage to limbal stem cells and/or changes in the limbal stem cell niche microenvironment due to intrinsic and extrinsic insults. This paper reviews the physical properties, synthesis, and degradation of HA. In addition, the interaction of HA with other extracellular matrix (ECM) components and receptor proteins are discussed. Finally, studies employing HA-based hydrogel scaffolds in the treatment of LSCD are reviewe