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Brazilian Archives of Biology and Technology, Volume: 57, Número: 3, Publicado: 2014
  • Biological traits and Life table parameters A and B biotype of Bemisia tabaci (Genn.) on cotton and rapeseed Agriculture, Agribusiness And Biotechnology

    Samih, Mohammad Amin; Zarabi, Mehdi; Yazdani, Maryam; Rouhani, Mohammad

    Resumo em Inglês:

    The aim of this work was to construct life table of Bemisia tabaci (Gen.) A and B (silverleaf whitefly B. argentifolii Bellows and Perring) biotype (Hem.: Aleyrodidae) on two host plants; cotton, (Gossypium hirsutum L.) and rapeseed, (Brassica napus L.). Experiments were conducted in a growth chamber under 24 ± 2ºC, 55±3% RH and 16:8 (L:D) h photoperiod on caged plants of cotton G. hirsutum L. (Varamin 76 variety) and rapeseed B. napus L. (global variety. The intrinsic rate of natural increase (r m), net reproductive rate (R0) and mean generation time (T) for B. tabaci A biotype was 0.1010 females per female per day, 18.4075 females per female and 30.079 day (d) on cotton; 0.1286, 30.6760 and 26.77 d on rapeseed; and for B biotype (B. argentifolii) those above respective parameters averaged 0.1033, 27.8426 and 32.74 d on cotton and 0.1750, 40.75 and 21.27 d on rapeseed. The total survival of A and B biotype from the egg to adult on cotton was 22.08 and 22.25, respectively. The results showed significant differences between the two biotype reared on either host plant for gross reproductive rate (GRR), net reproductive rate (R0 or NRR), intrinsic rates of increase (r m), finite rate of increase (λ), doubling time (DT) and mean generation times (Tc). To obtain a better understanding of the biology of these biotypes, Stable age distribution (Cx) and some other aspects of life history related to their hosts were also studied. Based upon the results, both biotypes showed a greater reproduction capacity on rapeseed than on cotton. Thus, rapeseed was more suitable host than cotton for two biotypes and this was an important factor in host plant selection for optimizing the control strategies of these major pests.
  • Enhanced biosynthesis of quercetin occurs as A photoprotective measure in Lycopersicon esculentum mill. under Acute UV-B exposure Agriculture, Agribusiness And Biotechnology

    Shourie, Abhilasha; Tomar, Pushpa; Srivastava, Deepika; Chauhan, Rahul

    Resumo em Inglês:

    Lycopersicon esculentum respond to UV-B by enhanced synthesis of flavonoid quercetin, a strong antioxidant that helps the plants to well acclimatize to UV-B stress. Three weeks old plants of L. esculentum were subjected to acute UV-B irradiation for 20, 40 and 60 minutes daily until 28 days and analyzed for the morphological and biochemical changes. UV-B exposure for 40 and 60 minutes considerably affected the growth and biomass of L. esculentum. The leaves were deformed, developed chlorosis and abscised early as compared to the unexposed plants. Biomass declined by 35% and total chlorophyll decreased by 24.7% due to disintegration of chloroplasts. Enhancement was seen in the content of carotenoids, anthocyanins and total flavonoids by 15, 33.3 and 22.8%, respectively, which was attributed to the photoprotective role of these compounds as potential quenchers of excess excitation energy. Quercetin content decreased on UV-B exposure to 20 and 40 min, and thereafter increased significantly by 5.19% on 60 min of exposure. This pattern probably indicated that the over-expression of genes involved in its biosynthesis such as phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), flavanone 3-hydroxylase (F3H) and dihydroflavonol 4-reductase (DFR) occurred only after certain threshold exposure (60 min), which could be the strategy for developing tolerance against UV-B stress in L. esculentum.
  • Growth curve, biochemical profile and phytochemical analyses in calli obtained from the procambium segments of Bacupari Agriculture, Agribusiness And Biotechnology

    Santos Filho, Plinio Rodrigues dos; Santos, Breno Régis; Barbosa, Sandro; Vieira, Letícia Rios; Freitas, Natália Chagas de; Dias, Daniele Ferreira; Santos, Marcelo Henrique dos

    Resumo em Inglês:

    Garcinia brasiliensis, popularly known as Bacupari, is native to the Amazon and commonly used in folk medicine for its therapeutic properties. This plant is rich in bioactive compounds like benzophenones. However, there are no works about the in vitro establishment and achievement of secondary metabolites in this plant. Thus, the aim of this work was to determine the growth curve and to perform the biochemical and phytochemical analyses in calli obtained from the procambium segments of Bacupari. The growth curve of calli followed a sigmoidal pattern, with four distinct phases (lag, exponential, linear, deceleration). Total soluble sugars were higher on the inoculation day and the reducing sugars on the 20 th day. Amino acids increased from the 60 th day up to the stabilization on the 120 th day. The protein content varied, but it seemed to be related to the amino acids metabolism. The phytochemical screening showed the presence of phenolic and flavonoid compounds in the calli and the HPLC analysis allowed the identification of Fukugetin, Guttiferone A and 7-epiclusianone.
  • Evaluation of inorganic and organic bone components after application of an apatite-coated Al2O3 implants as scaffolds for bone repair Human And Animal Health

    Maia Filho, Antonio Luiz Martins; Amaral, Fabrício Pires de Moura do; Martin, Airton Abrahão; Soares, Luís Eduardo Silva

    Resumo em Inglês:

    The aim of this work was to study the influence of uncoated and apatite-coated Al2O3 implants on bone regeneration after 30 days of surgery in New Zealand white rabbits. Twelve samples of Al2O3 implants were prepared and half of them (n = 6) were apatite-coated by the modified biomimetic method. Three experimental groups were tested as Group C - control, surgery procedure without cerami c implant, Group Ce - uncoated Al 2O3 implants (n = 6) and Group CeHA - apatite-coated Al2O3 implants (n = 6). The mineralization of the Al2O3 implants was analyzed in bone fragments using FT-Raman spectroscopy. Raman peaks at 959 cm-1 and 2940 cm-1 evaluated the inorganic and organic bone content, respectively. In vivo citotoxicity was analyzed using micronucleus test. Inorganic and organic content were higher in CeHA samples than in Ce and C (CeHA > Ce > C). FT-Raman spectroscopy showed that the higher the deposition of the organic matrix, more mineralization occurred. The micronucleus test showed that the uncoated and apatite-coated Al2O3 implants were non-cytotoxic and safe to in vivo applications.
  • Hepatoprotective effects of Iranian Hypericum scabrum essential oils against oxidative stress induced by acetaminophen in rats Human And Animal Health

    Dadkhah, Abolfazl; Fatemi, Faezeh; Farsani, Mohsen Eslami; Roshanaei, Kambiz; Alipour, Mahdi; Aligolzadeh, Hadi

    Resumo em Inglês:

    This studied examined the protective role of Hypericum scabrum oils (100 and 200 mg/kg b.w, i.p) on acetaminophen-induced liver damages in the rat. The hepatic oxidative/antioxidant parameters such as lipid peroxidation (LP), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and ferric reducing ability of plasma (FRAP) were measured 2, 4, 8, 16 and 24h after the treatments confirmed by histopathological consideration. The results indicated that increased levels of hepatic LP and FRAP and SOD activity were reversed in the rats treated with oils. In addition, the depleted GSH were compensated with the oil treatments. The protective effect of the oils was further confirmed by the histophatological examination carried out on liver biopsies. The data pointed out that H. scabrum oil could modulate the hepatic toxicity induced by the APAP through adjusting the oxidative stress/antioxidant parameters and could be of potential candidate for the treatment of acetaminophen induced oxidative stress liver damages.
  • In vitro antimicrobial activity and characterization of mangrove isolates of streptomycetes effective against bacteria and fungi of nosocomial origin Human And Animal Health

    Das, Arijit; Bhattacharya, Sourav; Mohammed, Abuelgasim Yegoup Hassan; Rajan, Subbaramiah Sundara

    Resumo em Inglês:

    The study aimed at determining the in vitro antimicrobial activity of alkaliphilic and halotolerant actinomycetes isolated from a mangrove ecosystem and identification of a potent strain. Twenty five isolates of actinomycetes were isolated from the sediment samples of Valapattanam mangrove swamp in Kerala, India. Antimicrobial activity of four selected actinomycete isolates was determined against bacterial and fungal pathogens of nosocomial origin by agar well diffusion method. Molecular characterization of the potent isolate was performed by 16S rDNA sequencing. Isolate no I-1 significantly inhibited Staphylococcus aureus ATCC 25923 (12 mm), S. aureus (15±0.05 mm), S. citreus (20±0.5 mm), Bacillus cereus (17±0.2 mm) and Serratia marcescens (12 mm). It also demonstrated effective antifungal action against Penicillium sp. (12±0.2 mm), Candida albicans (20±0.5 mm), C. parapsilosis (12 mm) and Cryptococcus neoformans (12 mm). Morphological study revealed that all the isolated actinomycetes belonged to the genus Streptomyces. Based on 16S rDNA sequence data, the selected isolate I-1 was shown to be closely related to Streptomyces xiamenensis. The results revealed that the mangrove ecosystem of Valapattanam harboured a rich consortium of many potent actinomycetes, which could synthesize novel bioactive compounds of pharmacological significance.
  • Production of leptospiral LipL32 antigen in Pichia pastoris and its use in an enzyme-linked immunosorbent assay Human And Animal Health

    Monte, Leonardo Garcia; Leal, Fernanda Munhoz Dos Anjos; Hartwig, Daiane Drawanz; Vasconcellos, Sílvio Arruda; Brihuega, Bibiana; Dellagostin, Odir Antonio; Hartleben, Cláudia Pinho

    Resumo em Inglês:

    The production of recombinant LipL32 protein using Escherichia coli has been used extensively for the development of vaccines and diagnostic tests for leptospirosis. However, E. coli has demonstrated limitations, including low yield and lack of post-translational modifications. In this study, rLipL32 was produced in eukaryotic expression system (Pichia pastoris) and evaluated the antigen by enzyme-linked immunosorbent assay (ELISA). The yield obtained from the culture supernatant reached 270 mg/L and ELISA showed an accuracy of 95.34%. In summary, the production of rLipL32 using P. pastoris did not impair the antigenic characteristics of this antigen and ensured its use for detecting the leptospiral antibodies in swine sera.
  • The effects of intramuscular or intravenous injections of gonadotropin releasing hormone at fixed-time artificial insemination on pregnancy rates of Bos indicus beef cows Human And Animal Health

    Demeterco, Danilo; Henry, Darren Dwayne; Mercadante, Vitor Rodrigues Gomes; Lamb, Graham Cliff; Gaievski, Francisco Romano; Weiss, Bruno; Turbay, Gustavo Nascimento; Segui, Márcio Saporski; Weiss, Romildo Romualdo; Betiol, Melina Andreia Formighieri; Kozicki, Luiz Ernandes

    Resumo em Inglês:

    The effect of an intramuscular versus intravenous administration of gonadotropin releasing hormone (GnRH) at fixed-time AI (FTAI) on the pregnancy rates of crossbred Bos indicus beef cows was evaluated. Pluriparous nursing calv cows (n=120) were synchronized as follows: d 0 cows received a 2.0 mg injection of estradiol benzoate (EB) and insertion of a controlled intravaginal progesterone releasing device containing 0.558 g of progesterone, d 8 removal of the progesterone device , a 0.15 mg injection of prostaglandin F2α (PGF), a 1.0 mg injection of EB, and 400 IU injection of equine chorionic gonadotropin. Fifty-four hr after PGF, all cows were exposed to FTAI and a 0.084 mg injection of GnRH was administered either via Vena caudalis (n=60), or via Longissimus dorsi (n=60). Cows were inseminated with the same sire and by a single AI technician. Pregnancy was determined by the transrectal ultrasonography on d 40 after AI. Cows receiving the intravenous administration of GnRH had higher (P = 0.04) pregnancy rates than the cows receiving the intramuscular injection of GnRH (65 vs 46.6%, respectively). It was concluded that the intravenous administration of GnRH at the time of AI improved the pregnancy rates of crossbred Bos indicus beef cows submitted to FTAI.
  • Application of Chinese Jun-Cao technique for the production of Brazilian Ganoderma lucidum strains Biological And Applied Sciences

    Rolim, Leonardo do Nascimento; Sales-Campos, Ceci; Cavalcanti, Maria Auxiliadora de Queiroz; Urben, Arailde Fontes

    Resumo em Inglês:

    Ganoderma lucidum is a medicinal mushroom traditionally used in China against a wide range of diseases such as cancer and also for its prevention. In this work, commercial Chinese strains G. lucidum were compared to wild Brazilian strains aiming to determine the cultivation potential through the use of Jun-Cao. Six formulations were tested and the strains presented good response to the applied method. In general, the mixture between the grass and wood was well suited for the basidiomycetes, contributing to the preparation of substrates that generated better results in Jun Cao.
  • Assessment of viability of sperm cells of Litopenaeus vannamei on cryopreservation Biological And Applied Sciences

    Uberti, Marcela Fornari; Vieira, Felipe do Nascimento; Salência, Helena Ragibo; Vieira, Genyess da Silva; Vinatea, Luis Alejandro

    Resumo em Inglês:

    Aiming at assessing the cryopreservation potential of Litopenaeus vannamei sperm cells, 74 spermatophores were manually extracted from the sexually mature individuals. After the toxicity test to define the cryoprotectant concentration, suspensions of spermatic cells were cryopreserved in the groups in freezing solutions comprising different cryoprotectants such as dimethyl sulfoxide (DMSO) and ethylene glycol (EG) at 10% concentration. Each treatment was divided in subgroups for storage in liquid nitrogen during 0, 30, 60 and 90 days, in triplicate. After thawing at 25ºC for 40 seconds, cell viability in the suspensions was analyzed under the microscope in eosin-nigrosin stain and flow cytometry. There were no significant differences between the cryoprotectants used. For all the treatments, lower and higher mortalities occurred in the 0 and 90 days, respectively. By applying the eosin-nigrosin technique, lower and higher mortalities were 23.17 and 82.11% for DMSO and 29.94 and 83.72% for EG, while the flow cytometry registered mortalities of 2.42 and 55.13% for DMSO and 0.90 and 55.56% for EG. The Spearman correlation coefficient indicated a positive correlation (R=0.91) between the two techniques used. It was concluded that there was a decrease in cell viability within a longer cryopreservation time.
  • Cell density and solvent are critical parameters affecting formazan evaluation in MTT assay Biological And Applied Sciences

    Gasque, Kellen Cristina da Silva; Al-Ahj, Luana Polioni; Oliveira, Rodrigo Cardoso; Magalhães, Ana Carolina

    Resumo em Inglês:

    The aim of this study was to establish the more accurate protocol for fibroblast cell viability using MTT assay. NIH/3T3 fibroblasts were seeded at the following cell densities: 3.125x10³; 1.156x10(4); 3.125x10(4); 1.156x10(5) and 3.125x10(5) cells/cm². Following 24h of seeding, MTT was added to the wells. After 4h of the MTT addition, different solvents were added to solubilize the formazan crystals: 1) HCl/SDS group- 20% SDS and 0.01 M HCl; 2) EtOH/ HAc group-50% ethanol and 1% acetic acid; 3) DMSO group- 99.5% dimethyl sulfoxide; and 4) PropOH group- 99.5% isopropanol. The absorbance values were measured using a spectrophotometer at 570 nm. The data were analyzed by 2-way ANOVA (p<0.05) and showed that the absorbance average varied according to the number of cells and solvents: HCl/SDS (0 to 0.13), EtOH/HAc (0 to 0.22), DMSO (0.76 to 1.31) and PropOH (0.66 to 1.04). The DMSO and PropOH groups presented the most appropriate protocols for NIH/3T3 fibroblasts cell viability, especially at the density of 1.156x10(4) cells/cm².
  • Effects of hydrolysis and digestion in vitro on the activity of bovine plasma hydrolysates as inhibitors of the angiotensin I converting enzyme Biological And Applied Sciences

    Gómez Sampedro, Leidy Johanna; Zapata Montoya, José Edgar

    Resumo em Inglês:

    The angiotensin I-converting enzyme (ACE) inhibiting activity of bovine plasma hydrolyzates obtained by Alcalase 2.4 L at different degrees of hydrolysis (DH) was evaluated. For the evaluation of ACE inhibition (ACEI), Hippuryl-His-Leu was used as substrate and the amount of hippuric acid liberated by non-inhibiting ACE was determined by spectrophotometry at 228 nm. The results showed that the enzymatic hydrolysis increased the ACEI activity as compared with the un-hydrolyzed plasma. The highest activity was onbtained with a DH of 6.7%. The peptide fractions with the maximum activity were isolated using ultrafiltration membranes, ion exchange chromatography and high performance liquid chromatography on reverse phase (RP-HPLC). The fraction with highest ACEI activity, showed an IC50 of 0.18 mg/mL and contained peptides with sequences AGATGVTISGAG, YSRRHPEYAVS, Q(K)AW and L(l)I(I)VR, which were determined by MALDI-TOF-TOF. It was also found that after submitting such fraction to digestive conditions in vitro, the ACEI activity remained constant.
  • Somatic embryogenesis and plant regeneration in Wedelia calendulacea Less. an endangered medicinal plant Biological And Applied Sciences

    Sharmin, Shamima Akhtar; Alam, Md. Jahangir; Sheikh, Md. Mominul Islam; Sarker, Kanak Kanti; Khalekuzzaman, Muhammad; Haque, Md. Anwarul; Alam, Mohammad Firoz; Alam, Iftekhar

    Resumo em Inglês:

    In this work, plant regeneration via somatic embryogenesis was achieved from leaf and internode derived callus of Wedelia calendulacea, an endangered medicinal plant. Primary callus was induced by culturing leaf disc and internode explant on Murashige and Skoog medium supplemented with 2.0 mg L-1 of 2,4-D under light condition. Transfer of embryogenic callus on a reduced concentration of 2,4-D facilitated somatic embryo development while calluses remained unorganized at the same 2,4-D level. A histological analysis confirmed somatic embryo by revealing the presence of a closed vascular system in the developing embryos and lack of a vascularconnection with surrounding callus tissues. Somatic embryos germinated into plantlets upon transfer on MS medium containing 1.0 mg L-1 BAP plus 0.5 mg L-1 GA3. Plantlets were acclimatized successfully and survived under soil condition. This is the first on somatic embryogenesis of W.calendulacea. This result could facilitate genetic transformation of this important medicinal plant.
  • Evaluation of a functional soy product with addition of soy fiber and fermented with probiotic kefir culture Food Science And Technology

    Baú, Tahis Regina; Garcia, Sandra; Ida, Elza Iouko

    Resumo em Inglês:

    The objective of this study was to evaluate the chemical, sensory properties and stability of a functional soy product with soy fiber and fermented with probiotic kefir culture. The product was characterized by the chemical composition, color and sensory analysis. The stability of the product was evaluated by pH, acidity, viscosity, firmness, syneresis measurements and cells counts. The functional soy product presented better chemical composition and difference in color compared to the fermented product without fiber. Sensory analysis showed that the functional soy product had good acceptance and had better firmness and reduced syneresis compared to fermented product without fiber. The lactic acid bacteria counts decreased slightly during 28 days at 4°C of the storage and the product showed good microbiological stability. The functional soy product due to high Lactococcus lactis counts could be considered as a probiotic for the entire storage period.
  • Lactobacilli isolated from Algerian goat's milk as adjunct culture in dairy products Food Science And Technology

    Marroki, Ahmed; Bousmaha-Marroki, Leila

    Resumo em Inglês:

    In this study, nineteen Lactobacillus isolated from Algerian goat's milk, 13 belonging to L. plantarum, three to L. pentosus, two to L. rhamnosus and one to L. fermentum, were examined in vitro in order to be used as adjunct culture in dairy products. The strains were tested for their proteolytic activity, sensory and safety properties. Strains LbMS16 and LbMS21 L. plantarum and LbMF25 L. rhamnosus presented the highest proteolytic activity. All the tested lactobacilli were able to grow on MRS agar containing 0.5 and 1% (W/V) of oxgall, whereas none produced biogenic amine (BA) from the four tested amino acids and were resistant to pH 2.0 and 3.0, but some strains were able to grow at pH 3.5. None of examined strains were β-haemolytic when grown in hors blood agar. Result of antibiotic resistance showed that all the strains were susceptible to penicillin, erythromycin and resistant to vancomycin. Diacetyl production was observed for two strains of L. plantarum and one of L. rhamnosus. Most of strains were able to produce pleasant flavours in fermented milk and gave a good acceptance. According to these results, the strains LbMS16, LbMS21and LbMF25 could be good candidates to be used as adjunct culture, playing a probiotic role in dairy products manufacture in Algeria.
  • Optimization of the production of extracellular α-amylase by Kluyveromyces marxianus IF0 0288 by response surface methodology Food Science And Technology

    Stergiou, Panagiota-Yiolanda; Foukis, Athanasios; Theodorou, Leonidas; Papagianni, Maria; Papamichael, Emmanuel

    Resumo em Inglês:

    The aim of this work was to study the production of extracellular α-amylase by Kluyveromyces marxianus IF0 0288 using optimized nutritional and cultural conditions in a complex yeast medium under aerobic batch fermentation. By applying the conventional "one-variable-at-a-time" approach and the response surface methodology, the effect of four fermentation parameters (type of carbon source, initial culture pH, temperature, and incubation time) on the growth and α-amylase production was evaluated. The production of α-amylase during 60 h of fermentation increased 13-fold under optimized conditions (1% starch, pH 6.0, 30ºC) in comparison to the conventional optimization method. The initial pH value of 6.13 and temperature of 30.3ºC were optimal conditions by the response surface methodology, leading to further improvement (up to 13-fold) in the production of extracellular α-amylase. These results constituted first evidence that K. marxianus could be potentially used as an effective source of extracellular α-amylase.
  • Effect of biologically treated petroleum sludge on seed germination and seedling growth of Vigna unguiculata (L.) Walp. (Fabaceae) Environmental Sciences

    Sangeetha, Jeyabalan; Thangadurai, Devarajan

    Resumo em Inglês:

    The present investigation was carried out to study the response of different concentrations of treated petroleum sludge on seed germination, root and shoot length and tolerance of Vigna unguiculata (L.) Walp. The biologically treated petroleum sludge with bacterial consortium showed 54.8% reduction in total petroleum hydrocarbons. Treated sludge was utilized with agricultural soil in known concentration for the assessment of growth of V. unguiculata. A remarkable absence of seed germination was observed at higher sludge concentration. The different concentrations of treated petroleum sludge showed severe decline on the length, weight and vigour index of the tested seedlings with increasing sludge concentrations. The results showed that the difference in rate of seed germination was significant among various concentrations. Under environmental stress condition, germination is the most critical phase of life cycle in crop plants. In this present study, the high oil content found to alter the osmotic relation between seed and water and thus reduce the amount of water absorbed. It was concluded that the concentration of nutrients and oil present in the treated sludge were toxic to the plant.
  • Heavy metal accumulation in the leaves, stem and root of the invasive submerged macrophyte Myriophyllum spicatum L. (Haloragaceae): an example of Kadin Creek (Mugla, Turkey) Environmental Sciences

    Yabanli, Murat; Yozukmaz, Aykut; Sel, Fatma

    Resumo em Inglês:

    In this study, the existence of heavy metals such as chromium (Cr), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) their distribution in the organs of plant and their bioaccumulation rates in water samples and Myriophyllum spicatum which were collected from the Kadin Creek in seasonal periods between 2011 and 2012 were analyzed. Heavy metal concentrations in the mineralized plant and water samples were determined with Inductive coupled plasma with mass spectroscopy (ICP-MS). Results showed the maximum heavy metal concentrations, in the root and minimum heavy metal concentrations, except chromium, in the stem. The distribution of heavy metals As, Cd, Hg and Pb was in the form of root > leaf > stem; the distribution of Cr was in the root > stem > leaf. There was a strong negative correlation between the suspended solid matter and heavy metal concentrations in the plant tissues. Heavy metal accumulation showed increase generally in fall. Heavy metals in the water were sorted as Pb > Cr > As > Hg > Cd by their mean concentrations. According to the factor data of bioconcentration, the order of heavy metal accumulation in the plant was As > Cr > Pb > Hg > Cd.
  • Chemical inhibition of the contaminant Lactobacillus fermentum from distilleries producing fuel bioethanol Engineering, Technology And Techniques

    Oliva Neto, Pedro de; Lima, Fabíola Aliaga de; Silva, Ketrin Cristina da; Silva, Douglas Fernandes da; Carvalho, Ana Flavia Azevedo; Santos, Catarina dos

    Resumo em Inglês:

    The purpose of this study was to determine the Minimum Inhibitory Concentration (MIC) of pure or mixed chemicals for Saccharomyces cerevisiae and Lactobacillus fermentum in the samples isolated from distilleries with serious bacterial contamination problems. The biocides, which showed the best results were: 3,4,4' trichlorocarbanilide (TCC), tested at pH 4.0 (MIC = 3.12 mg/l), TCC with benzethonium chloride (CBe) at pH 6.0 (MIC = 3.12 mg/l) and TCC mixed with benzalkonium chloride (CBa) at pH 6.0 (MIC = 1.53 mg /l). If CBa was used in sugar cane milling in 1:1 ratio with TCC, a 8 times reduction of CBa was possible. This formulation also should be tested in fermentation steps since it was more difficult for the bacterium to develop resistance to biocide. There was no inhibition of S. cerevisiae and there were only antibiotics as an option to bacterial control of fuel ethanol fermentation by S. cerevisiae.
  • Scale up of production in a bioreactor of a halotolerant protease from moderately halophilic Bacillus sp. isolated from soil Engineering, Technology And Techniques

    Prasad, Roopa; Abraham, Theruvath Koshy; Nair, Ananthakrishnan Jayakumaran

    Resumo em Inglês:

    Studies were conducted on the production of protease by moderately halophilic Bacillus sp. on agro-industrial waste materials. The bacterium could efficiently use many agro wastes as substrates but wheat bran supported maximum enzyme production. To ascertain the performance of the process in shake flasks and lab scale bioreactor, experiments were conducted to analyse protease activity utilizing wheat bran as cost effective substrate. The studies unveiled that pH 7.0, temperature 30°C and static conditions were optimal for enzyme production in flask level fermentation. In scale-up fermentation, at optimal pH and temperature, agitation rate of 50 rpm was best for protease production. The enzymatic nature was studied in 10% SDS gels with BSA (2.5 mg/mL) as substrate and banding pattern was compared with undigested BSA as control. The endoprotease nature and the kinetics of protease activity were confirmed. The enzyme retained 37% of its activity even at 5 M NaCl concentration. The proteolytic activity was also confirmed by casein zymogram analysis. The fermentation medium containing inexpensive substrates, physical conditions and ability of Bacillus sp. to exhibit protease activity on a large scale could collectively be useful for commercial production.
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