Citric Pulp Research Articles

Phytase production by white-rot fungi cultivated in liquid medium with particulate agro-industrial byproducts

This study aimed to screen phytase-producing basidiomycetes by submerged cultivation (SmC) with particulate agro-industrial byproducts and evaluate the enzyme's thermal and pH stability. Five among eight fungal species produced high phytase activity (> 300 U mL-1) after seven days in SmC. Ganoderma sp., the best phytase producer (1130 U mL-1), was grown in a liquid medium with particulate agro-industrial byproducts (coffee husks, citric pulp, sugarcane bagasse, and soybean hulls). Soybean hulls increased phytase activity (16%) and productivity (2.3-fold). The residual phytase activity was determined after 120 min incubation in different pH (pH 3, 5, 7, and 9) and temperatures (30, 50, and 70 oC). Phytase activity remained stable at pH ranging from 3 to 9, with 100% activity retention after 120 min at pH 7. Furthermore, Phytase retained more than 60% activity when incubated for 120 min from 30 oC to 70 oC. Our findings support future studies using Ganoderma sp. and particulate soybean hulls for phytase production for potential use in the animal feed industry.

Decolorization of remazol brilliant blue R with laccase from Lentinus crinitus grown in agro-industrial by-products.

Lentinus crinitus is a white-rot fungus that produces laccase, an enzyme used for dye decolorization. Enzyme production depends on cultivation conditions, mainly agro-industrial by-products. We aimed to produce laccase from Lentinus crinitus with agro-industrial by-products for dye decolorization. Culture medium had coffee husk (CH) or citric pulp pellet (CP) and different nitrogen sources (urea, yeast extract, ammonium sulfate and sodium nitrate) at concentrations of 0, 0.7, 1.4, 2.8, 5.6 and 11.2 g/L. Enzymatic extract was used in the decolorization of remazol brilliant blue R. CH medium promoted greater laccase production than CP in all evaluated conditions. Urea provided the greatest laccase production for CH (37280 U/L) as well as for CP (34107 U/L). In CH medium, laccase activity was suppressed when carbon-to-nitrogen ratio changed from 4.5 to 1.56, but the other nitrogen concentrations did not affect laccase activity. For CP medium, reduction in carbon-to-nitrogen ratio from 6 to 1.76 increased laccase activity in 17%. The peak of laccase activity in CH medium occurred on the 11th day (41246 U/L) and in CP medium on the 12th day (32660 U/L). The maximum decolorization within 24 h was observed with CP enzymatic extract (74%) and with CH extract (76%).

Effects of cycloheximide on the mortality of Atta sexdens leaf-cutting worker ants

Leaf-cutting ants live symbiotically with a fungus that they cultivate on the plant leaves that they cut. The innumerous studies on the plant selection mechanism used by leaf-cutting ants show the researchers’ interest in this issue. Many classical studies propose that plants are selected according to the fungus garden nutritional needs and the absence of potentially harmful substances. This hypothesis is corroborated by behavioral experiments using cycloheximide (fungicide) with citric pulp or forage plants greatly accepted by leaf-cutting ants. According to this hypothesis, under the action of a fungicide, the fungus emits an allomone that informs worker ants that some food is inadequate to its growth. Although some authors state that the cycloheximide “fungicide” used is specific and non toxic to ants, our findings are distinct. In our study, various concentrations of cycloheximide were administered orally to leaf-cutting worker ants in a citric pulp paste diet. After the ingestion period, the ants were isolated and offered the symbiotic fungus for 21 days and the mortality rate was evaluated. As expected, the treatment with 0.01% cycloheximide showed a low mortality rate (8.86%). At 0.1%, the mortality rate was mild (27.85%), and treatment with 1% cycloheximide resulted in moderate mortality (45.57%). In contrast, the positive control with 0.1% sulfluramid showed a high mortality rate (91.14%). Therefore, we concluded that the ingestion of high concentrations of cycloheximide results in a moderate mortality rate in leaf-cutting worker ants.

Gibberellic Acid Production by Different Fermentation Systems Using Citric Pulp as Substrate/Support.

Gibberellic acid (GA3) is an important phytohormone, a member of gibberellins family, which acts as a promoter and regulator of plant growth. This study aimed to evaluate GA3 production by Fusarium moniliforme LPB03 and Gibberella fujikuroi LPB06 using different techniques of fermentation, solid state fermentation (SSF), submerged fermentation (SmF), and semisolid state fermentation (SSSF), and different types of bioreactors. In all techniques, citric pulp (CP), a subproduct obtained from the extraction of orange juice, was employed as the substrate/support. GA3 production by SSF reached 7.60 g kg−1 and 7.34 g kg−1 in Erlenmeyer flasks and column bioreactors, respectively. For SmF, the highest concentration of GA3 obtained was 236.00 mg L−1 in Erlenmeyer flasks, 273.00 mg L−1 in a 10 L stirred tank reactor (STR), and 203.00 mg L−1 in a 1.5 L bubble column reactor (BCR). SSSF was conducted with a CP suspension. In this case, GA3 concentration reached 331.00 mg L−1 in Erlenmeyer flasks and 208 mg L−1 in a BCR. The choice of the fermentation technique is undoubtedly linked to the characteristics and productivity of each process. The methods studied are inexpensive and were found to produce good proportions of GA3, making them suitable for several applications.

SUBSTITUIÇÃO DE FONTE DE AMIDO POR FIBRA SOLÚVEL EM DETERGENTE NEUTRO NA DIETA DE VACAS

Resumo Conduziu-se este trabalho com o objetivo de avaliar os efeitos da substituição do milho por polpa cítrica sobre o desempenho de vacas leiteiras. Utilizaram-se nove vacas (três canuladas no rúmen) da raça Holandesa, pluríparas, com 80 ± 24 dias de lactação e produção média diária de 20 ± 0,58 kg de leite. Os animais foram confinados em tie stall, com cocho e bebedouro individuais. Utilizou-se um quadrado latino 3 x 3. Os períodos experimentais tiveram duração de 21 dias, sendo 14 de adaptação e sete de coleta. Os tratamentos foram constituídos de 100% milho grão (MG), 50% milho grão e 50% polpa cítrica (MP) e 100% polpa cítrica (PC). Não houve diferenças significativas na ingestão dos nutrientes (MS, MO, FDN, FDA, PB, amido) entre dietas. O tratamento com polpa cítrica produziu maior proporção de acetato em relação aos demais, bem como maior relação acetato/propionato. As médias de pH situaram-se entre 5,86 e 7,35. As médias de N-NH3 apresentaram maiores diferenças nos tempos 2 e 3 horas pós-alimentação. Não houve diferenças entre as dietas para produção total de leite corrigido para 4% de gordura, proteína, lactose, extrato seco total (EST) e nitrogênio uréico do leite (NUL).

Dioxins, furans, biphenyls, arsenic, thorium and uranium in natural and anthropogenic sources of phosphorus and calcium used in agriculture

The aim of this study was to assess the presence of dioxins, furans and biphenyls, and the inorganic contaminants such as arsenic (As), thorium (Th) and uranium (U) in three main products used in Agriculture in Brazil: feed grade dicalcium phosphate, calcined bovine bone meal and calcitic limestone. The first two are anthropogenic sources of phosphorus and calcium, while calcitic limestone is a natural unprocessed mineral.Regarding to dioxin-like substances, all samples analyzed exhibited dioxins (PCDD) and furans (PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) concentrations below limit of detection (LOD). In general, achieved is in accordance with regulation in Brazil where is established a maximum limit in limestone used in the citric pulp production (0.50pg WHO-TEQ g−1). In addition, reported data revealed very low levels for limestone in comparison with similar materials reported by European legislation.As result for toxic metals, achieved data were obtained using Instrumental Neutron Activation Analysis (INAA). On one hand, limestone sample exhibits the largest arsenic concentration. On another hand, dicalcium phosphate exhibited the largest uranium concentration, which represents a standard in animal nutrition. Therefore, it is phosphorus source in the animal feed industry can be a goal of concern in the feed field.

Carrying and Effect of Granulated Baits Formulated with Entomopathogenic Fungi among Atta sexdens rubropilosa Colonies (Hymenoptera: Formicidae)

The present study aimed to evaluate the carrying and effect of (dry) granulated baits containing conidia of entomopathogenic fungi among colonies of the leaf-cutting ant Atta sexdens rubropilosa in the laboratory. This bait type was chosen to facilitate its eventual commercial use. Two applications were performed: in the first, baits with 1x108 conidia/g were utilized while in the second employed concentrations 5 to 8.6 times greater. The baits were formulated with a citric pulp base, with 2 isolates of Beauveria bassiana, 1 of Paecilomyces lilacinus and 1 of Isaria fumosorosea. The following controls were utilized: (I) baits with sulfluramid insecticide, (II) without active ingredient, and (III) Acalypha spp. leaf discs. It was verified that the baits containing fungal conidia were rapidly carried to the nest interior in both applications and were rejected minimally. Thus, the (dry) granulated bait formulation appears to be an adequate vehicle for entomopathogenic fungi. At the doses and concentrations utilized, the fungi provoked only limited worker mortality, not killing the colonies. Given the rapid carrying and low rejection, a higher conidial dose per colony can, perhaps, kill them. Thus, it is inferred that all the isolates tested present potential as an agent to control colonies of leaf-cutting ants.

Behaviour of confined sheep fed with different concentrate sources

In this study we examined the effects of different feed concentrates on sheep behaviour. Our hypothesis was that citric pulp would stimulate rumination and be capable of replacing other concentrates traditionally used for feeding in confinement, to reduce the risk of urolithiasis. Ten adult Santa Inês sheep were distributed in a Latin square with five different diets, one control diet with 80% hay and 20% commercial feed and four diets containing 30% coast-cross hay and 70% of the following concentrates: pelleted citrus pulp, citrus pulp meal, cornmeal or wheat bran. After 21d of adaptation to each one of the five diets, the sheep were visually monitored for 24 h at 3 min intervals to record the time spent ruminating, time spent eating and time spent resting; the animals' positions (standing or lying down) were also noted. Daytime was considered to be from 06:00h to 18:00h. The data were evaluated using ANOVA, with Tukey post-hoc test or throughout Two-sample T test for circadian and position assessment. Citrus pulp diets resulted in time spent ruminating similar to the control diet (601, 590 and 669 min, respectively), but greater (P<0.05) than the cornmeal group (421min), which showed that citrus pulp generated effective rumination. The estimated saliva production in the control diet (26L) was greater than in the other groups, and was greater in the citrus pulp groups (24L/d) than cornmeal (21L/d). Feeding with cornmeal led to shorter time spent eating and time spent ruminating than all other diets. The sheep had higher time spent resting at night when fed concentrates (P<0.05). For all diets, about 90% of the time spent ruminating occurred with the animals lying down. Pelleted citrus pulp, citrus pulp meal and to a lesser degree wheat bran, led to adequate time spent ruminating. The use of citrus pulp can act as a preventive management measure to reduce the incidence of urolithiasis in sheep flocks.

Effect of supplementation frequency on intake, behavior and performance in beef steers grazing Marandu grass

Eighteen Nellore steers, with an average initial body weight (BW) of 312±10.6kg, grazing Brachiaria brizantha cv. Marandu were assigned to three experimental treatments consisting of different supplementation frequencies (daily [DAI], Monday through Friday [M–F] and Monday, Wednesday and Friday [MWF]). The supplement was offered at a rate of 35.0gkg−1 BW per week and contained 565gkg−1 corn gluten meal-60, 235gkg−1 dry sugarcane yeast, 140gkg−1 citric pulp and 60gkg−1 mineral premix. Animal performance (ADG), dry matter (DM) intake, DM digestibility, daily grazing time and pattern of supplement intake were evaluated in the steers from February to May. The forage DM intake was estimated using the alkane pair C32:C33 and the DM apparent digestibility using the alkane C35 as an internal marker. A reduction in supplementation frequency did not affect animal performance, with an average weight gain of 0.69kg/d. Supplementation frequency did not affect (P>0.05) forage and total (forage+supplement) DM intakes or DM digestibility. However, forage and total DM intakes and DM apparent digestibility decreased significantly (P<0.01) from March to May, whereas grazing time during the day (from 06:00h to 18:00h) increased by 22% in the same period. The animals receiving infrequent supplementation (M–F and MWF) spent a greater portion of the day grazing when not given the supplement compared to days on which they received the supplement. Reducing the frequency of supplementation from 7 to 3d per week is a viable method to reduce labor and equipment utilization costs as this reduction did not affect intake, digestibility or animal performance in the present study.

Effect of forced aeration on citric acid production by Aspergillus sp. mutants in SSF

Citric acid (CA) is one of the most important products of fermentation in the world. A great variety of agro-industrial residues can be used in solid state fermentation. Aspergillus niger parental strain (CCT 7716) and two strains obtained by mutagenesis (CCT 7717 and CCT 7718) were evaluated in Erlenmeyer flasks and glass columns using citric pulp (CP) as substrate/support, sugarcane molasses and methanol. Best results using glass columns (forced aeration) were found in the fourth day of fermentation: 278.4, 294.9 and 261.1 g CA/kg of dry CP with CCT 7716, CCT 7718 and CCT 7717, respectively. In Erlenmeyer flasks (aeration by diffusion) CA reached 410.7, 446.8 and 492.7 g CA/kg of dry CP with CCT 7716, CCT 7718 and CCT 7717, respectively. The aeration by diffusion improved CA production by the three strains. A data acquisition system specially developed for biotechnological processes analysis was used to perform the respirometric parameters measurement.

Effect of chitosan on 17β-estradiol secretion in C57/BL/6J mice exposed to PCBs

The aim of this study was to assess the presence of dioxins, furans and biphenyls, and the inorganic contaminants such as arsenic (As), thorium (Th) and uranium (U) in three main products used in Agriculture in Brazil: feed grade dicalcium phosphate, calcined bovine bone meal and calcitic limestone. The first two are anthropogenic sources of phosphorus and calcium, while calcitic limestone is a natural unprocessed mineral.Regarding to dioxin-like substances, all samples analyzed exhibited dioxins (PCDD) and furans (PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) concentrations below limit of detection (LOD). In general, achieved is in accordance with regulation in Brazil where is established a maximum limit in limestone used in the citric pulp production (0.50 pg WHO-TEQ g− 1). In addition, reported data revealed very low levels for limestone in comparison with similar materials reported by European legislation.As result for toxic metals, achieved data were obtained using Instrumental Neutron Activation Analysis (INAA). On one hand, limestone sample exhibits the largest arsenic concentration. On another hand, dicalcium phosphate exhibited the largest uranium concentration, which represents a standard in animal nutrition. Therefore, it is phosphorus source in the animal feed industry can be a goal of concern in the feed field.

EFEITO DE DIFERENTES FONTES ENERGÉTICAS NA PREDISPOSIÇÃO PARA UROLITÍASE EM CABRITOS

Six goats randomly divided into three groups were used in a 4 X 3 Youden Square design, using four distinct diets [control (C), citric pulp (CP), wheat meal (WM) and rice meal (RM)] in order to evaluate which diet will predispose the formation of uroliths. Serum calcium and phosphorous were determined, as well as urinary pH, density, calcium and phosphorous. The goats fed RM had the highest serum and urinary phosphorous values (5.34±1.71 and 156.9±85.5 mmol/L, respectively), while the animals that received CP had the lowest values for blood and urine phosphorous (2.29±0.36 and 2.02±1.24 mmol/L, respectively). The results of urine pH showed that CP diet caused alkaline urine (8.44±0.33), with higher values than WM and RM (6.27±0.29 and 6.37±0.54, respectively). The urine from one animal that received WM diet and from another that received RM diet presented triple phosphate crystals, while the urine from the goats receiving CP did not present any of these crystals. A determinant factor for crystal formation is the high phosphorous concentration in the urine. Acidic urine pH does not prevent the formation of crystals if urinary phosphorous concentrations are high. KEYWORDS: citrus pulp; goats; rice meal; urinary calculi; wheat meal.

Fontes de fibra na alimentação do pacu: desempenho, composição corporal e morfometria intestinal

O objetivo deste estudo foi avaliar os efeitos da utilização de diferentes ingredientes fibrosos nas dietas sobre o desempenho, a composição corporal e a morfometria intestinal de juvenis de pacu. Foram avaliadas cinco dietas isoproteicas (23% de proteína digestível), isoenergéticas (3250kcal de energia digestível/kg) e isofibrosas (9% de fibra bruta), sendo a principal fonte fibrosa de cada constituída por farelo de soja, casca de soja, farelo de girassol e polpa cítrica; esta última em dois níveis de inclusão (30 e 45%). Foram utilizados 300 juvenis de pacu (25,12±0,78 gramas), alojados em 25 aquários (200 litros). Os melhores resultados de crescimento e conversão alimentar foram obtidos com as dietas contendo farelo de soja e farelo de girassol. As dietas contendo casca de soja e polpa cítrica prejudicaram o desempenho dos juvenis de pacu, e o efeito negativo foi acentuado com o aumento da inclusão de polpa cítrica. Além disto, somente nos peixes alimentados com a dieta com 45% de polpa cítrica foi observada diminuição na densidade de vilosidades por área no epitélio intestinal. A partir dos resultados obtidos, pode-se concluir que alguns ingredientes fibrosos podem afetar negativamente o desempenho e as características do epitélio intestinal de juvenis de pacu.

Chitosan Functional Finishing of Bamboo Pulp Fiber Fabric in Aqueous Citric Acid Media

The bamboo pulp fiber fabric was treated by chitosan with low molecular weight in aqueous citric acid. The effect of citric acid concentration, chitosan concentration, treatment time and reaction temperature on anti-creasing and mechanical properties of the fabric were studied, respectively. Meanwhile, the optimal finishing condition was obtained. The anti-wrinkle and hygroscopic properties of all processed fabrics improved markedly at the optimal technology. However, the breaking strength of the fabric decreased slightly after the optimal treatment. FT-IR characterization of the treated fabric showed that the chitosan was crosslinked on the bamboo pulp fiber fabric and the ester linkage was formed between the citric acid and bamboo pulp cellulose. The antibacterial property of the chitosan treated fabric increased dramatically. The resulting bamboo pulp fiber fabric treated by chitosan is a natural ecological textile product, having the various application and more potential chemical modification.

INCREASE IN PHYTASE SYNTHESIS DURING CITRIC PULP FERMENTATION

Citric pulp bran was used for the first time as substrate for phytase synthesis under solid-state fermentation. An A. niger FS3 phytase strain was applied in optimization studies. A Plackett-Burman screening design identified significant physicochemical variables. These preselected variables were subsequently optimized using a central composite rotational design (CCRD). The maximum phytase production was achieved with the following optimum variables: 30°C temperature, 65% initial moisture content, 0.3 M Na-citrate buffer concentration, initial pH 5.0, and 1.5% urea concentration. An overall 4.3-fold improvement in phytase production was successfully achieved.

Phytase produced on citric byproducts: purification and characterization

Citric pulp is an agro-industrial residue from the citrus processing industry with low inorganic phosphorus content applied in animal feed. A new bioprocess was developed to produce and purify a new phytase generated on citric pulp fermentation by Aspergillus niger FS3. The phytase was purified by cationic-exchange, anionic-exchange chromatography and chromatofocusing steps. From SDS–PAGE analysis, the molecular weight of the purified phytase was calculated to be 108 kDa. The phytase had an optimum pH of 5.0–5.5 and an optimum temperature of 60°C. The phytase displayed high affinity for phytate, and the Km was 0.52 mM. The purified phytase was sufficiently able to withstand pelleting temperatures, retaining sufficiently high phytate-degrading activity.

Monitoring fermentation parameters during phytase production in column-type bioreactor using a new data acquisition system

Fermentation parameters for phytase production in column-type bioreactor were monitored using a new data acquisition system. There are a number of studies reporting phytase production in flasks, but a lack of data about microorganism respiration behaviour during phytase production using column bioreactor. The objectives of this work were the monitoration of fermentation parameters during phytase production and its relation with fungal growth and forced air. Phytase production by A. niger FS3 increased with forced air. The O(2) consumption and CO(2) production during solid-state fermentation were monitored by sensors (in the bottom and top of the columns) linked to controllers, recorded by acquisition software and processed by Fersol2(®) software tool. Phytase synthesis was associated with fungal growth. Therefore, phytase could be used to estimate FS3 biomass formed in citric pulp degradation.

A new alternative to produce gibberellic acid by solid state fermentation

Gibberellic acid (GA3) is an important hormone, which controls plant's growth and development. Solid State Fermentation (SSF) allows the use of agro-industrial residues reducing the production costs. The screening of strains (four of Gibberella fujikuoroi and one of Fusarium moniliforme) and substrates (citric pulp, soy bran, sugarcane bagasse, soy husk, cassava bagasse and coffee husk) and inoculum preparation study were conducted in order to evaluate the best conditions to produce GA3 by SSF. Fermentation assays were carried out in erlenmeyers flasks at 29°C, with initial moisture of 75-80%. Different medium for inoculum production were tested in relation to cells viability and GA3 production by SSF. F. moniliforme LPB 03 and citric pulp were chosen for GA3 production. The best medium for inoculum production was citric pulp extract supplemented with sucrose. GA3 production by SSF reached 5.9 g /kg of dry CP after 3 days of fermentation.

A simplified model for A. Niger FS3 growth during phytase formation in solid State fermentation

A simplified model to describe fungal growth during citric pulp fermentation for phytase production was described for the first time. Experimental data for biomass growth were adjusted to classical mathematical growth models (Monod and Logistic). The Monod model predictions showed good agreement with the experimental results for biomass concentration during 96 hours of fermentation. Parameters such as yield of biomass from oxygen (Y X/O), maintenance coefficient (m) and specific growth rate (µ) were compared showing a good correlation between the data and the model. An alternative method for biomass determination in this process was developed since a great correlation was found between biomass growth and enzyme formation.

DEGRADABILIDADE IN SITU DAS RAÇÕES DE VACAS DA RAÇA HOLANDÊS EM LACTAÇÃO COM SUBSTITUIÇÃO DO MILHO POR POLPA CÍTRICA

The substitution of the ground corn grain by the citrus pulp in the concentrate of diets of dairy cows pans (100% ground corn grain, 50% ground corn grain and 50% citrus pulp, and 100% citrus pulp) was evaluated. Nine lactating dairy cows Holstein were used in a Latin square 3 x 3, was evaluated the in situ degradation of the diets and the passage rate of the liquid phase. The inclusion of citric pulp resulted in elevation of the tax of degradation of the matter dries, of the soluble fraction of the matter it dries and of the time of colonization for the microorganisms you ruminate, however it didn’t alter the potential degradability of the matter dries of the concentrate. The inclusion of citric pulp increased the effective degradability of the matter dries of the bulky, and this presented decreasing values in all the concentrate for the taxes of passage 2, 5 and 8%/h, respectively. The potential degradation of DM of the roughage was 82.16%, and the rate degradation was 1.33%/h. The inclusion of citric pulp in the diets, in growing proportions, they alter the parameters of degradation in situ of the concentrate KEY WORDS: By-product, pectin, starch.