Bioremediation of colour of methyl violet and phenol from a dye-industry waste effluent using Pseudomonas spp. isolated from factory soil

Methyl violet, a basic dye, is manufactured using phenol and dimethylaniline as the raw materials. It is, therefore likely that the waste effluent arising from such units may contain the dye and unused chemicals. Since such pollutants may be toxic, their removal becomes necessary. The studies were therefore aimed at their bioremediation using microbial species.
Four species of Pseudomonas , namely Ps. alcaligenes, Ps. mendocina, Ps. putida biovar B and Ps. stutzeri , were isolated from cattle dung enrichments and the soil samples in the premises of the factory manufacturing methyl violet, nearby Pune.
All the four species of Pseudomonas were able to remove phenol and methyl violet with simultaneous reduction in chemical oxygen demand (COD), total organic carbon (TOC) and ammoniacal nitrogen from the waste effluent and the removal was found to be optimum at the original alkaline pH (range 7.45–10.6) of the waste effluent, at ambient temperature (28 ± 2°C under aerated culture condition, at inoculum density of 1.5 × 10⁸ cells ml⁻¹ of the waste effluent and incubation period of 24–48 h. Thus, Pseudomonas spp. isolated from the environment of the dye industry itself and thus naturally adapted could be used for bioremediation of these pollutants.     

Metabolic engineering of Synechococcus elongatus for photoautotrophic production of mannitol

With multiple applications in food, pharmaceutical, and chemical industries as antioxidant or nonmetabolizable sweetener; the bioproduction of d -mannitol is gaining global attention, especially with photosynthetic organisms as hosts. Considering the sustainability prospects, the current work encompasses metabolic engineering of a widely used cyanobacterial strain, Synechococcus elongatus PCC 7942, and two newly isolated fast-growing cyanobacterial strains; S. elongatus PCC 11801 and S. elongatus PCC 11802, for mannitol production. We engineered these strains with a two-step pathway by cloning genes for mannitol-1-phosphate dehydrogenase (mtlD) and mannitol-1-phosphatase (mlp), where the mtlD expression was under the control of different promoters from PCC 7942, namely, P_rbc225, P_cpcB300, P_cpcBm1, P_rbcLm17, and P_rbcLm15. The strains were tested under the “switch conditions,” where the growth conditions were switched after the first 3 days, thereby resulting in differential promoter activity. Among the engineered strains of PCC 11801 and PCC 11802, the strains possessing P_rbc225-mtlD module produced relatively high mannitol titers of 401 ± 18 mg/L and 537 ± 18 mg/L, respectively. The highest mannitol titer of 701 ± 15 mg/L (productivity 60 mg/L.d, yield 895 µM/OD₇₃₀) was exhibited by the engineered strain of PCC 7942 expressing P_cpcB300-mtlD module. It is by far the highest obtained mannitol yield from the engineered cyanobacteria.     

Hepatic polyamine metabolism in children with Reye's syndrome.

Acute mitochondrial insult has been suggested as a primary reason for the clinical, histopathological and biochemical abnormalities seen in Reye's syndrome. However, the etiology of mitochondrial dysfunction has not been identified. Polyamines have been known to alter the mitochondrial structure and function. Influenza infection may cause an increase in ornithine decarboxylase activity and thereby channel ornithine for polyamine biosynthesis, leading to mitochondrial dysfunction in Reye's syndrome. To test this hypothesis, the hepatic concentrations of polyamines, polyamine-metabolizing enzymes and urea cycle enzyme activities in Reye's syndrome patients were determined and compared with patients who died from illnesses other than Reye's syndrome. The hepatic concentration of putrescine, spermidine and spermine were increased in Reye's syndrome patients. The activity of ornithine decarboxylase was elevated but, due to the small number of samples, these values did not reach statistical significance. Ornithine carbamoyltransferase activity was decreased in the liver of Reye's syndrome patients. Our results suggest that increased synthesis of polyamines from ornithine may initiate mitochondrial injury in Reye's syndrome.     

Clinicopathologic Predictors of Survival in Patients with Desmoplastic Melanoma

Background and Objectives

Desmoplastic melanoma is a unique subtype of melanoma which typically affects older patients who often have comorbidities that can adversely affect survival. We sought to identify melanoma-specific factors influencing survival in patients with desmoplastic melanoma.

Methods

Retrospective review from 1993 to 2011 identified 316 patients with primary desmoplastic melanoma. Clinicopathologic characteristics were correlated with nodal status and outcome.

Results

Fifty-five patients (17.4%) had nodal disease: 33 had a positive sentinel lymph node biopsy and 22 developed nodal recurrences (no sentinel lymph node biopsy or false-negative sentinel lymph node biopsy). Nodal disease occurred more often in younger patients and in cases with mixed compared with pure histology (26.7% vs. 14.6%); both of these variables significantly predicted nodal status on multivariable analysis (p<0.05). After a median follow-up of 5.3 years, recurrence developed in 87 patients (27.5%), and 111 deaths occurred. The cause of death was known in 79 cases, with 47 deaths (59.5%) being melanoma-related. On multivariable analysis, Breslow thickness, mitotic rate ≥1/mm² and nodal status significantly predicted melanoma-specific survival (p<0.05).

Conclusions

Nodal status predicts melanoma-specific survival in patients with desmoplastic melanoma. However, since patients with desmoplastic melanoma represent an older population, and a considerable proportion of deaths are not melanoma-related (40.5%), comorbidities should be carefully considered in making staging and treatment decisions in this population.     

Cultivable Bacterial Diversity of Alkaline Lonar Lake, India

Aerobic, alkaliphilic bacteria were isolated and characterized from water and sediment samples collected in the winter season, January 2002 from alkaline Lonar lake, India, having pH 10.5. The total number of microorganisms in the sediment and water samples was found to be 10²–10⁶ cfu g⁻¹ and 10²–10⁴ cfu ml⁻¹, respectively. One hundred and ninety-six strains were isolated using different enrichment media. To study the bacterial diversity of Lonar lake and to select the bacterial strains for further characterization, screening was done on the basis of pH and salt tolerance of the isolates. Sixty-four isolates were subjected to phenotypic, biochemical characterization and 16S rRNA sequencing. Out of 64, 31 bacterial isolates were selected on the basis of their enzyme profile and further subjected to phylogenetic analysis. Phylogenetic analysis indicated that most of the Lonar lake isolates were related to the phylum Firmicutes, containing Low G+C, Gram-positive bacteria, with different genera: Bacillus, Paenibacillus, Alkalibacillus, Exiguobacterium, Planococcus, Enterococcus and Vagococcus. Seven strains constituted a Gram-negative bacterial group, with different genera: Halomonas, Stenotrophomonas and Providencia affiliated to γ-Proteobacteria, Alcaligenes to β-Proteobacteria and Paracoccus to α-Proteobacteria. Only five isolates were High G+C, Gram-positive bacteria associated with phylum Actinobacteria, with various genera: Cellulosimicrobium, Dietzia, Arthrobacter and Micrococcus. Despite the alkaline pH of the Lonar lake, most of the strains were alkalitolerant and only two strains were obligate alkaliphilic. Most of the isolates produced biotechnologically important enzymes at alkaline pH, while only two isolates (ARI 351 and ARI 341) showed the presence of polyhydroxyalkcanoate (PHA) and exopolysaccharide (EPS), respectively.     

Intralesional Injection of Rose Bengal Induces a Systemic Tumor-Specific Immune Response in Murine Models of Melanoma and Breast Cancer

Intralesional (IL) injection of PV-10 has shown to induce regression of both injected and non-injected lesions in patients with melanoma. To determine an underlying immune mechanism, the murine B16 melanoma model and the MT-901 breast cancer model were utilized. In BALB/c mice bearing MT-901 breast cancer, injection of PV-10 led to regression of injected and untreated contralateral subcutaneous lesions. In a murine model of melanoma, B16 cells were injected into C57BL/6 mice to establish one subcutaneous tumor and multiple lung lesions. Treatment of the subcutaneous lesion with a single injection of IL PV-10 led to regression of the injected lesion as well as the distant B16 melanoma lung metastases. Anti-tumor immune responses were measured in splenocytes collected from mice treated with IL PBS or PV-10. Splenocytes isolated from tumor bearing mice treated with IL PV-10 demonstrated enhanced tumor-specific IFN-gamma production compared to splenocytes from PBS-treated mice in both models. In addition, a significant increase in lysis of B16 cells by T cells isolated after PV-10 treatment was observed. Transfer of T cells isolated from tumor-bearing mice treated with IL PV-10 led to tumor regression in mice bearing B16 melanoma. These studies establish that IL PV-10 therapy induces tumor-specific T cell-mediated immunity in multiple histologic subtypes and support the concept of combining IL PV10 with immunotherapy for advanced malignancies.     

Substituent activity relationship studies on new azolo benzoxazepinyl oxazolidinones

In an effort to discover potent antibacterials based on the entropically favored 'bioactive conformation' approach, a series of novel tricyclic molecules mimicking the conformationally constrained structure of Linezolid is reported. Based on the initial tricyclic molecule 1, the benzazepine derivative 2 was designed where the tricyclic structure had more flexibility around C-N bond compared to 1. While, the molecule 2 was less active, the molecule 3 showed promising antibacterial activity presumably after having obtained rigidity due to pyrrole ring. The syntheses, SAR studies, and evaluation of 3 as a lead compound are reported.     

Protective effects of a thromboxane synthetase inhibitor and continuous arteriovenous hemofiltration in rat endotoxic shock

We determined the efficacy of continuous arteriovenous hemofiltration (CAVH) and a thromboxane synthetase inhibitor (TSI) on survival and their effect on TXA₂, PGI₂, TNFα, and IL-1β production in rat endotoxemia. Thirty-six endotoxemic rats were randomized to one of 4 groups: (A) no TSI, sham CAVH; (B) no TSI, CAVH; (C) TSI, sham CAVH; and (D) TSI, CAVH. Either CAVH (Group B) or pretreatment with TSI (Group C) resulted in increased survival time. CAVH did not prevent the rise in TX (Group B). TNFα levels at 2 h after LPS infusion were higher in Group D compared to Group B (26.1 ± 3.7 vs 13.2 ± 4.3 ng/mL, P < 0.05) respectively. IL-1β was detected earlier in Groups C,D when compared to Groups A,B (P < 0.02). TNFα and IL-1β were not ultrafiltered. CAVH and the inhibition of TX synthesis independently improved survival in endotoxemia, however, their beneficial effects were not additive. While TSI may improve survival by blocking TXA₂ production, the salutary effects of CAVH appear to be from removal of an undetermined TXA₂ dependent mediator. TNFα and IL-1β concentrations do not appear to influence survival times in this model.     

Effect of ammonium acetate-induced hyperammonemia on metabolism of guanidino compounds.

Guanidino compounds are synthesized from arginine in various tissues such as liver, kidney, brain, and skeletal muscle. Guanidino compounds such as arginine and creatine play an important role in nitrogen metabolism, whereas other guanidino compounds such as guanidinosuccinic acid and alpha-N-acetylarginine are known toxins. In order to understand the changes in the metabolism of guanidino compounds during ammonia toxicity, we investigated the effect of hyperammonemia induced by an ammonium acetate injection on the levels of guanidino compounds in plasma, liver, kidney, and brain of rats. Control animals were injected with an equal volume of saline. Blood and tissues were removed 1 h following ammonium acetate or saline injection and guanidino compounds were analyzed by high-performance liquid chromatography. Plasma and kidney levels of guanidinosuccinic acid were significantly elevated in rats challenged with ammonium acetate. Brain alpha-N-acetylarginine levels were also significantly higher in rats injected with ammonium acetate as compared to those in controls. Our results suggest that guanidinosuccinic acid and alpha-N-acetylarginine may play an important role in hyperammonemia.     

Bioremediation of an industrial effluent containing monocrotophos

Almost 30% of the precious agricultural output of India is lost owing to pest infestation. In India, pesticide consumption for protecting crops is about 3% of the total world consumption. Monocrotophos (MCP), an organophosphorus insecticide, is widely used to control insects on crops. Being readily water soluble and highly toxic, its removal from wastewater generated during manufacture becomes inevitable. Bioremediation of wastewater containing MCP by Arthrobacter atrocyaneus, Bacillus megaterium, and Pseudomonas mendocina was highest at pH 8.0, but maximum reduction in Chemical Oxygen Demand (COD) was at pH 7.0. Removal of MCP and reduction in COD by B. megaterium and Ps. mendocina were highest at 35°C, while with A. atrocyaneus, it was maximum at 30°C, under aerated culture condition and inoculum density of 10⁸ cells/ml. Use of pure cultures for bioremediation of effluent containing MCP appears to be the first such attempt. Received: 26 September 2001 / Accepted: 5 February 2002