Alka Mehta

Pseudomonas putida is a multifaceted bacteria with the capability of doing bioremediation for various compounds present in the environment or released through different industrial processes. This review presents the degradation pathway of many noxious acyclic, homocyclic, and heterocyclic compounds, which have serious adverse effects. Some of these hydrocarbons can cause harm to humans by either being carcinogenic, like naphthalene, nitrobenzene, and carbazole, or being addictive, like nicotine. Even the simplest of the hydrocarbons like alkanes are capable of causing pneumonia or simply dryness and irritation to the human body. In addition, the acyclic isoprenoids are known to act as a skin irritant or a respiratory and Central nervous system (CNS) depressant. Plasmids, which are small, extrachromosomal deoxyribonucleic acid (DNA) molecules present inside the cell, have the power to replicate independently. This review focuses on the participation of the different active genes of individual plasmids of P. putida responsible for the degradation of different compounds. It also gives a proper degradation pathway for each toxic compound stated above. In this article, the knowledge available in research papers about the compounds and the advantage of using P. putida for its removal for a better, safer, and sound environment is presented in simple language understandable to an initiator, as well as providing comprehensive information for the seasoned researcher in the field.

The waterbodies have been polluted by various natural and anthropogenic activities. The aquatic waste includes ammonia as one of the most toxic pollutants. Several biological treatment systems involving anoxic and semi anoxic bacteria have been proposed for reducing nitrogen loads from wastewater and increasing the efficiency and cost effectiveness. These bacteria play a vital role in the processes involved in the nitrogen cycle in nature. However, the enrichment, sustainability and identification of bacterial communities for wastewater treatment is an important aspect. Most of the chemolithotrophs are unculturable hence their identification and measurement of abundance remains a challenging task. In this study the different bacteria involved in total nitrogen removal from the wastewater are enriched for 700 days under anoxic condition. The synthetic wastewater containing 0.382 g/L of ammonium chloride was used. Molecular identification of the bacteria involved in various steps of the nitrogen cycle was carried out based on amplification of functional genes and 16S rRNA gene Polymerase chain reaction followed by DNA sequencing. Change in the abundance of chemolithotrophs was studied using qPCR. The mutual growth of various nitrifiers along with anaerobic bacteria were identified by molecular characterisation of DNA at various time intervals with the different genes involved in the nitrogen cycle. Nitrosomonas species like Nitrosomonas europaea were identified throughout the batch scale studies possessing the genes associated with ammonia oxidizing bacteria and nitrite oxidizing bacteria which act as a complete ammonia oxidizer. The uncultured species of Nitrospira and anammox bacteria were also observed which predicts the coexistence of the anammox and comammox bacteria in a batch scale study. The coexistence of the semi anoxic and anoxic bacteria helped in the growth of these bacteria for a longer duration of time. The nitrite produced by the comammox during nitrification can be utilized by anammox as an electron carrier. The other species of denitrifiers like Pseudomonas denitrificans and Aminobacter aminovorans were also observed. It is concluded that the enrichment of semi anoxic and anoxic bacteria was faster with the increase in growth of the bacteria involved in nitrification, comammox, anammox and partial denitrification process. The bacterial growth is enhanced and the efficiency is increased which can be further used in the development of small pilot scale bioreactor for total nitrogen removal. Graphical abstract

Quantification of mycotoxins in foodstuffs is extremely difficult as a limited amount of toxins are known to be presented in the food samples. Mycotoxins are secondary toxic metabolites, made primarily by fungal species, contaminating feeds and foods. Due to the presence in globally used grains, it is an unpreventable problem that causes various acute and chronic impacts on human and animal health. Over the previous few years, however, progress has been made in mycotoxin analysis studies. Easier techniques of sample cleanup and advanced chromatographic approaches have been developed, primarily high‐performance liquid chromatography. Few extremely sophisticated and adaptable tools such as high‐resolution mass spectrometry and gas chromatography–tandem MS/MS have become more important. In addition, Immunoassay, Advanced quantitative techniques are now globally accepted for mycotoxin analysis. Thus, this review summarizes these traditional and highly advance methods and their characteristics for evaluating mycotoxins.

Background: Thrombosis represents as the prime contributor to the burden of diseases, worldwide. Conventional anticoagulants for thrombosis therapy have a common bleeding side effect. Bioactive peptides are studied to be an effective alternative for currently available therapeutic drugs. Objective: In this study, VITPOR AI peptide, a previously reported coagulation FXIIa inhibitor from Nori (Porphyra yezoensis), was assessed for its inhibitory activity against FXIIa and its in vivo mode of action. Methods: In vivo efficacy as well as the antithrombotic property of the peptide was evaluated in mice model by ex vivo activated Partial Thromboplastin Time assay, tail transection model and whole blood clotting time. The enzyme kinetics was studied using chromogenic substrate assay. Results: The kinetic behaviour of VITPOR AI showed that the peptide is a competitive inhibitor of FXIIa. Peptide showed significant inhibition of platelet adhesion and aggregation. VITPOR AI exhibited significant antithrombotic activity. Furthermore, ex vivo activated Partial Thromboplastin Time assay revealed that VITPOR AI exhibited potent anticoagulant activity in vivo. Tail bleeding assay revealed that the peptide did not prolong bleeding time in mice even at a higher dose of 5 mg/kg. Cytotoxicity studies of the peptide against human blood leukocytes indicated the safety of the peptide. Conclusion: VITPOR AI could be prospected as a potent anticoagulant with Factor XIIa inhibition, antiplatelet aggregation and antithrombotic activity. It was also studied to have no bleeding side effect.

Degradation or the removal of aflatoxin B₁ from agriculture commodities is very important because of its acute toxicity and economic loss due to rejection of about 25% contaminated agri produce. The present study aimed at using Pseudomonas putida for the aflatoxin B₁ (AFB₁) degradation and to understand the mechanism involved. AFB₁ degradation was studied with P. putida culture, culture supernatant, cell lysate, cell lysate in the presence of protease inhibitor, and heat-inactivated cell lysate. The remaining AFB₁ was qualitatively and quantitatively measured by thin-layer chromatography and HPLC with a UV detector. P. putida culture and culture supernatant showed 80% reduction in AFB₁ within 24 h of incubation. Cell lysate and the lysate in the presence of protease inhibitor showed the same reduction in 6 and 4 h respectively. The protease-inhibited lysate showed greater thermostability, broad pH range, and tolerance to some of the solvents and detergents in terms of aflatoxin B₁ degrading activity. The heat-inactivated lysate showed only 20% reduction in 24 h of incubation indicating loss of activity on heating. As cell-free supernatant and cell lysate are capable of reducing AFB₁ effectively, actively growing cells are not necessary for degradation. The active principle for degradation might be proteinaceous; therefore, heat-inactivated lysate is ineffective for reducing the AFB₁. These results showed that degradation of aflatoxin B₁ by P. putida might be an enzymatic process and could be used in a broad range of conditions.