Soil Chemical Analysis

Evaluation of thermophilic fungal consortium for organic municipal solid waste composting

Nanotechnology is currently at the forefront of scientific research and technological developments that have resulted in the manufacture of novel consumer products and numerous industrial applications using engineered nanomaterials (ENMs). With the increasing number of applications and uses of ENMs comes an increasing likelihood of nanoscale materials posing potential risks to the environment and engineered technical systems such as wastewater treatment plants (WWTPs). Recent scientific data suggests that ENMs that are useful in, for example, medical applications due to their novel physicochemical properties, may also cause adverse effects to the bacterial populations used in wastewater treatment systems. In this review, the toxicological effects of titanium nanoparticles (nTiO2), zinc oxide (nZnO), carbon nanotubes (CNTs), fullerenes (C60) and silver nanoparticles (AgNPs) to bacteria were examined. The results suggest that the potential ENMs risks to bacteria are non-uniform (need to be assessed case-by-case), and are dependent on numerous factors (e.g. size, pH, surface area, natural organic matter). Currently available data are therefore insufficient for evaluating the risks that ENMs pose in WWTPs. To fill these knowledge gaps, we recommend scenario specific studies aimed at improving our understanding on: (i) estimated volumes of ENMs in effluents, (ii) the antibacterial sensitivity of cultures within WWTPs towards selected ENMs, and (iii) processes improving the stability of ENMs in solutions. Two factors that merit consideration for elucidating the potential risks systematically are the toxicity mechanisms of ENMs to bacteria, and the influencing factors based on inherent physicochemical properties and environmental factors. Furthermore, the complexity of behaviour and fate of ENMs in real WWTPs requires case studies for assessing the ENMs risks to bacteria in vivo. The current laboratory results derived using simplified exposure media do not reflect actual environmental conditions.

The antibacterial effects of engineered nanomaterials: implications for wastewater treatment plants

The waste generated from industrial processes and operations including domestic wastes when treated partially and disposed in soil–water environment enter to lakes, streams, rivers, oceans and other water bodies. The pollutants get dissolved or lie suspended in water or get deposited on soil sediment beds. This results on aquatic and terrestrial pollution which ultimately impact ecosystems causing toxicity to biota and human beings. Industries such as petrochemical, pharmaceutical, insecticides and fertilizers generates the hazardous waste comprising of inorganic and organic compounds. Organic compounds mainly composed polycyclic aromatic hydrocarbons (PAHs), are one of the toxic environmental pollutant. This paper highlights the physicochemical properties, bioremediation treatment and its mechanism for the waste containing PAH. The process of biological remediation depends upon the metabolic action of microbe toward the contaminant which can be achieved by optimum water and nutrient supply and some other limiting factors. The enzymatic degradation gives the molecular approaches for bioremediation. The study also highlighted the molecular approaches which are helpful in revealing functional, structural and communal information about microbial diversity for exploring the routes of degradation pathway of bioremediation process and future scope to bioremediation of PAHs.

Molecular approaches for biodegradation of polycyclic aromatic hydrocarbon compounds: a review

Metal remediation and biodegradation potential of earthworm species on municipal solid waste: a parallel analysis between Metaphire posthuma and Eisenia fetida.

It is important to use renewable resources to maximize crop yields and minimize the environmental hazards associated with chemical residues. Composting is an age old practice for the biological conversion of organic waste to a humus-like substance which can enhance physical, chemical and biological soil properties. To explore the effect of microorganisms in the composting process, three potent bacterial isolates were selected. Their morphological, cultural and biochemical characteristics were identified, and 16S rDNA studies identified isolates B1U/1 and D3L/1 as Bacillus subtilis and isolate RAT/5 as Pseudomonas sp. Common organic wastes were composted using the selected isolates individually and as a consortium. The C/N ratio of each substrate reduced gradually to 25–30:1 within 120 days and remained constant thereafter. The reduction in NH4+ and NO3− ion concentrations also indicated compost maturity after 120 days. The pH of the mature compost was typically 7.0 ± 0.2, and the PO4−3 ion concentration was high throughout the decomposition process. This study describes the optimization of the composting process using a consortium of isolates from composted soil.

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Composting of common organic wastes using microbial inoculants

The accumulation of recalcitrant xenobiotic compounds is due to continuous efflux from population and industrial inputs that have created a serious impact on the pristine nature of our environment. Apart from this, these compounds are mostly carcinogenic, posing health hazards which persist over a long period of time. Metabolic pathways and specific operon systems have been found in diverse but limited groups of microbes that are responsible for the transformation of xenobiotic compounds. Distinct catabolic genes are either present on mobile genetic elements, such as transposons and plasmids, or the chromosome itself that facilitates horizontal gene transfer and enhances the rapid microbial transformation of toxic xenobiotic compounds. Biotransformation of xenobiotic compounds in natural environment has been studied to understand the microbial ecology, physiology and evolution for their potential in bioremediation. Recent advance in the molecular techniques including DNA fingerprinting, microarrays and metagenomics is being used to augment the transformation of xenobiotic compounds. The present day understandings of aerobic, anaerobic and reductive biotransformation by co-metabolic processes and an overview of latest developments in monitoring the catabolic genes of xenobiotic-degrading bacteria are discussed elaborately in this work. Till date, several reviews have come up, highlighting the problem of xenobiotic pollution, yet a comprehensive understanding of the microbial biodegradation of xenobiotics and its application is in nascent stage. Therefore, this is an attempt to understand the microbial role in biotransformation of xenobiotic compounds in context to the modern day biotechnology.

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Microbial transformation of xenobiotics for environmental bioremediation

Chemotherapeutic drugs remain the most efficacious treatment options for a many human cancers. However, the inability to deliver these drugs directly to cancerous cells often results in dose limiting and sometimes life-threatening adverse effects. Rather than developing new chemical moieties, researchers have begun focusing on the development of drug carriers, which are specifically designed to shuttle chemotherapeutics into malignant cells while sparing healthy cells. Charged nanoparticles have emerged as effective delivery platforms for several xenobiotic classes including anticancer agents, oligonucleotides and antibodies. Notably, peptide-based self-assembled nanostructures are of particular interest due to their biocompatibility, high drug loading capacity, and potential for customization for cell-specific targeting. We synthesized and studied the self-assembling properties of two charged, cell penetrating tri-peptides: H2N−Arg−Leu−Phe−OMe (S1) with Arg as cationic amino acid and Boc−Phe−Leu−Glu−OH (S2) with Glu as negatively charged amino acid. The fibrils and spherical self-assembled structures formed by S1 and S2, respectively, can encapsulate the chemotherapeutic drug Doxorubicin and facilitate intracellular drug delivery via endocytosis. Furthermore, S1- and S2-encapsulated Doxorubicin (Dox-S1, Dox-S2), like the unencapsulated drug, induced oxidative stress and mitochondrial dysfunction, activated the ATM/p53 signaling cascades, and triggered apoptosis in cancer cells. Thus, while the surface charge of molecular building blocks used to generate supramolecular assemblies influences the morphology of generated nanostructures, both cationic and anionic peptide-based assemblies are capable of functioning as drug delivery vehicles. 

Generation of Self‐Assembled Structures Composed of Amphipathic, Charged Tripeptides for Intracellular Delivery of Pro‐Apoptotic Chemotherapeutics

Isolation of probiotic lactococcus from milk and milk powder by serial dilution spread plate method to study antimicrobial activity

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Ieshita Pan

Papers

Composting of common organic wastes using microbial inoculants

Microbial transformation of xenobiotics for environmental bioremediation

Generation of Self‐Assembled Structures Composed of Amphipathic, Charged Tripeptides for Intracellular Delivery of Pro‐Apoptotic Chemotherapeutics

Isolation of probiotic lactococcus from milk and milk powder by serial dilution spread plate method to study antimicrobial activity

Compost Soil Amendment: An Approach to Enhance Crop Productivity by Improving Soil Physiology