Eliseo Cristiani-urbina | Instituto Politécnico Nacional (original) (raw)

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Papers by Eliseo Cristiani-urbina

The increasing phenol and phenolic wastes necessitates the screening of bacteria that are able to... more The increasing phenol and phenolic wastes necessitates the screening of bacteria that are able to degrade phenol. 115 bacterial isolates from several industrial sites and farms in Malaysia were screened for phenol degrading activity in minimal salt media (MSM) containing 0.5 gL -1 phenol. Thirty seven bacterial isolates exhibited phenol degrading activity and of this total, 6 isolates showed high phenol activity after 8 days of incubation. The isolate with the highest phenol degrading activity was subsequently identified as Acinetobacter sp. Strain AQ5NOL 1 based on Biolog TM GN plates and partial 16S rDNA molecular phylogeny. The optimum conditions for achieving high phenol degradation were 0.04% (w/v) (NH 4 ) 2 SO 4 , 0.01% (w/v) NaCl, pH 7, and temperature of 30 o C. Acinetobacter sp. Strain AQ5NOL 1 was found to degrade phenol of up to 1500 mgL -1 concentrations under the optimized conditions. The isolation of Acinetobacter sp Strain AQ5NOL 1 provides an alternative for the bioremediation of phenol and phenolic wastes.

Process Biochemistry, 2000

Lactic yeasts' produce some extracellular metabolites, as well as biomass, when cultivated in whe... more Lactic yeasts' produce some extracellular metabolites, as well as biomass, when cultivated in whey. Mixed cultures are able to use several sources of carbon simultaneously and therefore the use of mixed yeast cultures is proposed in order to reduce the whey COD and increase the biomass yield. Of the mixed yeast cultures tested, the highest biomass yield was obtained with Torulopsis cremoris and Candida utilis. C. utilis consumed some metabolic by products generated by T. cremoris. Repeated fed-batch culture of T. cremoris and C. utilis, carried out in an airlift bioreactor designed to operate variable volume processes, is a potential alternative for the treatment of whey, since it produces a high yield of biomass (0.75 g of biomass/g of lactose) and a greater COD removal efficiency (95.8%) than those reported in the literature.

New Biotechnology, 2009

Divalent nickel [Ni(II)] is a heavy metal widely used in several industrial processes. This metal... more Divalent nickel [Ni(II)] is a heavy metal widely used in several industrial processes. This metal causes serious environmental and public health problems; for this reason it is convenient to treat the industrial wastewaters polluted with nickel before discharging them to water bodies and/or soil. Biosorption is a potential alternative for the treatment of industrial effluents and aquatic ecosystems polluted with heavy metals. In this work, a low-cost, inactive biological material capable of removing divalent nickel from aqueous solutions was selected. Furthermore, the biosorption process catalyzed by the selected biomaterial was kinetically characterized and mathematically modeled.

Journal of Industrial Microbiology & Biotechnology, 2008

The main aim of this study was to investigate the influence of the sulfate ion on the tolerance t... more The main aim of this study was to investigate the influence of the sulfate ion on the tolerance to Cr(VI) and the Cr(VI) reduction in a yeast strain isolated from tannery wastewater and identified as Candida sp. FGSFEP by the D1/D2 domain sequence of the 26S rRNA gene. The Candida sp. FGSFEP strain was grown in culture media with sulfate concentrations ranging from 0 to 23.92 mM, in absence and presence of Cr(VI) [1.7 and 3.3 mM]. In absence of Cr(VI), the yeast specific growth rate was practically the same in every sulfate concentration tested, which suggests that sulfate had no stimulating or inhibiting effect on the yeast cell growth. In contrast, at the two initial Cr(VI) concentrations assayed, the specific growth rate of Candida sp. FGSFEP rose when sulfate concentration increased. Likewise, the greater efficiencies and volumetric rates of Cr(VI) reduction exhibited by Candida sp. FGSFEP were obtained at high sulfate concentrations. Yeast was capable of reducing 100% of 1.7 mM Cr(VI) and 84% of 3.3 mM Cr(VI), with rates of 0.98 and 0.44 mg Cr(VI)/L h, with 10 and 23.92 mM sulfate concentrations, respectively. These results indicate that sulfate plays an important role in the tolerance to Cr(VI) and Cr(VI) reduction in Candida sp. FGSFEP. These findings may have significant implications in the biological treatment of Cr(VI)-laden wastewaters.

Journal of Environmental Engineering and Science, 2003

Abstract: The manufacturing processes of tortillas, corn chips, tortilla chips, and related produ... more Abstract: The manufacturing processes of tortillas, corn chips, tortilla chips, and related products yield a liquid waste called nejayote. This waste causes serious pollution problems since its chemical oxygen demand is very high, from 25000 to 30000 ppm. To reduce the pollution potential ...

Journal of Biotechnology, 2010

Furthermore, this methodology permits the coating of all negative charges presented on the enzyme... more Furthermore, this methodology permits the coating of all negative charges presented on the enzyme surface, an advantage compared with the immobilization of the enzyme on agarose modified with PEI, where the enzyme is oriented by the riches area of negative charges on the surfaces and this could cause several subpopulations if the enzyme presents several rich areas on these residues on the surface. Therefore, due to the simplicity and short time-consuming of these modifications (performed in solid phase on an immobilized enzyme), this strategy seems to be a promising alternative and compatible with the rest of techniques in biocatalysis to develop new enantioselective biocatalysts.

Engineering in Life Sciences, 2003

A novel hybrid bioreactor was designed to remove volatile organic compounds from water contaminat... more A novel hybrid bioreactor was designed to remove volatile organic compounds from water contaminated with water-soluble gasoline components, and the performance of this new bioreactor was investigated. It was composed of two biotrickling filter sections and one biofilter section. ...

Biochemical Engineering Journal, 2008

Applied Biochemistry and Biotechnology, 2012

Journal of Industrial Microbiology & Biotechnology, 2011

Derepressed mutant PR-22 was obtained by N-methyl-N 0 -nitro-N-nitrosoguanidine (MNNG) mutagenic ... more Derepressed mutant PR-22 was obtained by N-methyl-N 0 -nitro-N-nitrosoguanidine (MNNG) mutagenic treatment of Cellulomonas flavigena PN-120. This mutant improved its xylanolytic activity from 26.9 to 40 U mg -1 and cellulolytic activity from 1.9 to 4 U mg -1 ; this represented rates almost 2 and 1.5 times higher, respectively, compared to its parent strain growing in sugarcane bagasse. Either glucose or cellobiose was added to cultures of C. flavigena PN-120 and mutant PR-22 induced with sugarcane bagasse in batch culture. The inhibitory effect of glucose on xylanase activity was more noticeable for parent strain PN-120 than for mutant PR-22. When 20 mM glucose was added, the xylanolytic activity decreased 41% compared to the culture grown without glucose in mutant PR-22, whereas in the PN-120 strain the xylanolytic activity decreased by 49% at the same conditions compared to its own control. Addition of 10 and 15 mM of glucose did not adversely affect CMCase activity in PR-22, but glucose at 20 mM inhibited the enzymatic activity by 28%. The CMCase activity of the PN-120 strain was more sensitive to glucose than PR-22, with a reduction of CMCase activity in the range of 20-32%. Cellobiose had a more significant effect on xylanase and CMCase activities than glucose did in the mutant PR-22 and parent strain. Nevertheless, the activities under both conditions were always higher in the mutant PR-22 than in the PN-120 strain.