Bioremediation of lindane-contaminated soils by combining of bioaugmentation and biostimulation: Effective scaling-up from microcosms to mesocosms.

The scaling-up of lindane-contaminated soils bioremediation from microcosms to mesocosms bioaugmentated with an actinobacteria quadruple culture and biostimulated with sugarcane filter cake (SCFC) was surveyed. Mesocosms of silty loam soil, clayey soil, and sandy soil were polluted with the pesticide, bioaugmented with the mixed culture, biostimulated with adequate amounts of 0.5 mm SCFC particles, and assessed during 63 days maintaining environmental parameters with minimal intervention. Samples were taken to determine residual lindane, heterotrophic microorganisms, enzymatic activities, and bioremediation effectiveness using ecotoxicity tests with Raphanus sativus, Lactuca sativa, and Lycopersicon esculentum. The bioaugmentation and biostimulation of the three soils improved lindane removal, microbial counts, and enzymatic activities, and reduced pesticide T1/2, regarding the values obtained in non-bioremediated controls. The removal process was significantly affected by the soil type, and the highest pesticide dissipation (82.6%) was detected in bioremediated sandy soil. Ecotoxicity tests confirmed the bioremediation success through a rise in the vigor index of seedlings compared to non-treated soils (R. sativus: 12-22%; L. sativa: 12-20%; L. esculentum: 30-45%). Finally, scanning electron microscopy corroborated soil colonization by actinobacteria. Successful scaling-up of the combined application of an actinobacteria quadruple culture and SCFC as an appropriate strategy for restoring lindane-polluted soils at mesocosms-scale was confirmed.

Enhanced bioremediation of lindane-contaminated soils through microbial bioaugmentation assisted by biostimulation with sugarcane filter cake.

Lindane is a toxic and persistent organochlorine pesticide, whose extensive use generated its accumulation in different environmental matrices. Bioremediation is a promising technology that can be used combining bioaugmentation and biostimulation processes to soil restoration. The aim of the present work was to determine the conditions of maximum lindane removal by bioaugmentation with an actinobacteria consortium and biostimulation with sugarcane filter cake (SCFC). The assays were carried out on lindane-contaminated silty loam (SLS), clayey (CS), and sandy (SS) soils. Through complete factorial designs, the effects of three abiotic factors (moisture content, proportion and size of SCFC particles) were evaluated on lindane removal. In addition, a response optimizer determined the optimal conditions for pesticide removal in bioaugmented and biostimulated soils, in the range of levels studied for each factor. In these conditions, bioaugmentation of biostimulated soils increased the pesticide removal (SLS: 61.4%, CS: 70.8%, SS: 86.3%), heterotrophic microbial counts, and soil enzymatic activities, and decreased lindane T1/2, regarding the non-bioaugmented biostimulated controls, after 14 days of assay. The values of these parameters confirmed the efficiency of the bioremediation process. Finally, the viability of the four strains was demonstrated at the end of the assay. The results indicate that the simultaneous application of bioaugmentation with the actinobacteria consortium and biostimulation with SCFC constitutes a promising tool for restoring soils contaminated with lindane, by using the optimal conditions obtained through the factorial designs.

Sugarcane growth and nutrition levels are differentially affected by the application of PGPR and cane waste.

Mineral and organic fertilization can be optimized by using rhizobacteria which increases dry matter, yield, and nutrients in the soil and plant, among the other biological inputs. However, the discovery of single microbes or a consortium that can benefit plants has been a challenge. In this context, this study aimed to evaluate the effects of Bacillus subtilis and Bacillus pumilus combined with mineral fertilization and sugar and alcohol industry by-products in presprouted and the initial growth phase of sugar cane seedlings. The study was carried out in two phases. Phase 1 included presprouted seedlings with T1 =  untreated control, T2 =  B. subtilis, T3 =  B. pumilus, and T4 =  B. subtilis + B. pumilus treatments. Phase 2 included the same treatments with four types of fertilization: F1 =  mineral fertilization, F2 =  mineral fertilization + vinasse, F3 =  mineral fertilization + filter cake, and F4 =  mineral fertilization + filter cake compost. Of the phase 1 treatments, T2 (B. subtilis) was the best promoter of root growth and the total dry matter compared to the control with an increase of 23.0% compared to the control. In phase 2, B. pumilus application, increased the total dry matter by 13%, the number of tillers by 37%, and the diameter of the tillers by 48% when combined with mineral fertilization. The combined application of B. subtilis and B. pumilus increased the phosphorus content by 13% in soil treated with mineral fertilization and filter cake compost. The results of the this study strongly suggest that the use of B. subtilis and B. pumilus together with these by-products can improve soil fertility parameters and decrease adverse effects associated with vinasse fertilization, in addition to providing shoot and root growth and providing collective synergy for a high yield of sugarcane production with environmental benefits.

Toxicological effects of the waste of the sugarcane industry, used as agricultural fertilizer, on the test system Allium cepa.

Sugarcane is cultivated in tropical countries for sugar and ethanol production. In Brazil, this culture is among the most profitable with a production of 658.7 million tons/harvest. Sugarcane filter cake (SCFC) is a waste rich in organic matter and micronutrients, but also contains toxic metals. As it has been used as fertilizer and there is not enough knowledge about its environmental impacts, this work assessed the genotoxicogenetic effects of raw SCFC and associations with soil and sugarcane bagasse (SCB), by Allium cepa tests. Six associations of SCFC + soil and five associations of SCFC + soil + SCB were tested at three moments of degradation: initial (T0), 3 and 6 months (T1 and T2). Genotoxicogenetic assays were performed with solid substrates of these associations and with their respective aqueous extracts. Chemical analysis showed a decrease in metals, total organic carbon and nitrogen after 6 months of biodegradation, complying with Brazilian laws. In general, the combination of SCFC + soil + SCB was better than using only SCFC. T0 solubilized samples of different associations composed by highest quantities of SCFC inhibited the MI and induced CA without presenting mutagenicity (except for 75%-SCFC + soil + SCB). T1 samples showed more cytotoxicity than T0 samples, and also presented genotoxic and mutagenic effects. Solid substrate and solubilized associations of SCFC + soil + SCB of T2 samples had no toxicity. These results suggest 6 months of biodegradation and the SCB adding as effective to reduce toxicogenetic effects induced by SCFC. Also, small proportions of SCFC interfered less on the A. cepa test-system when compared with those containing high quantities of residue.

Use of sugarcane filter cake and nitrogen, phosphorus and potassium fertilization in the process of bioremediation of soil contaminated with diesel.

This study evaluated the use of sugarcane filter cake and nitrogen, phosphorus and potassium (NPK) fertilization in the bioremediation of a soil contaminated with diesel fuel using a completely randomized design. Five treatments (uncontaminated soil, T1; soil contaminated with diesel, T2; soil contaminated with diesel and treated with 15 % (wt) filter cake, T3; soil contaminated with diesel and treated with NPK fertilizer, T4; and soil contaminated with diesel and treated with 15 % (wt) filter cake and NPK fertilizer, T5) and four evaluation periods (1, 60, 120, and 180 days after the beginning of the experiment) were used according to a 4 × 5 factorial design to analyze CO2 release. The variables total organic carbon (TOC) and total petroleum hydrocarbons (TPH) remaining in the soil were analyzed using a 5 × 2 factorial design, with the same treatments described above and two evaluation periods (1 and 180 days after the beginning of the experiment). In T3 and T5, CO2 release was significantly higher, compared with the other treatments. Significant TPH removal was observed on day 180, when percent removal values were 61.9, 70.1, 68.2, and 75.9 in treatments T2, T3, T4, and T5, respectively, compared with the initial value (T1).

The use of sugar and alcohol industry waste in the adsorption of potentially toxic metals.

One of the waste products of the industrial process of the sugar and alcohol agribusiness is filter cake (FC). This waste product has high levels of organic matter, mainly proteins and lipids, and is rich in calcium, nitrogen, potassium and phosphorous. In this work we characterized samples of FC from sugar and alcohol industries located in sugarcane-producing regions in Brazil and assessed the adsorption of potentially toxic metals (Cu(II), Cd(II), Pb(II), Ni(II) and Cr(III)) by this waste in mono- and multi-elemental systems, seeking to use FC as an adsorbent in contaminated environments. The characterization of FCs showed significant differences between the samples and the adsorption studies showed retention of over 90% of potentially toxic metals. In a competitive environment (multi-metallic solution), the FC was effective in adsorbing all metals except lead, but less effective compared to the mono-metallic solution. These results show the potential for use of this residue as an adsorbent in contaminated environments.

Chemical attributes, total organic carbon stock and humified fractions of organic matter soil submitted to different systems of sugarcane management / Atributos químicos, estoque de carbono orgânico total e das frações humificadas da matéria orgânica do solo em diferentes sistemas de manejo de cana-de-açúcar

Mechanized harvesting maintenance of trash from cane sugar and soil application of waste as vinasse and filter cake can improve the system of crop yield. Thus, this study aimed to evaluate the changes in the chemical, the stock of total organic carbon and humified organic matter fractions in an Oxisol cultivated with cane sugar with the following management systems: with sugarcane vinasse application (CCV), without application of burnt cane waste (CQS), with burnt cane vinasse application (CQV), with application of burnt cane filter cake (CQTF) and burnt cane with joint application of vinasse and filter cake (CQVTF). For reference we used an area of natural vegetation (NV), Cerrado sensu stricto. Treatment CQVTF showed improvement in soil chemical properties, increased inventory levels of total organic carbon TOC (values ranging from 21.28 to 40.02 Mg ha-1) and humified fractions of soil organic matter in relation to other treatments. The CQS area at a depth of 0-0.05 m, showed the greatest losses of soil TOC stocks (56.3%) compared to NV. The adoption of management presented CCV and chemical attributes of the soil TOC stocks equivalent to those observed in areas with CQV CQTF and despite the short period of adoption (3 years). The TOC correlated with the sum of bases (r = 0.76 **), cation exchange capacity (r = 0.59 **) and base saturation (r = 0.63 **), while the humic acids...(AU)

A colheita mecanizada com manutenção do palhiço da cana-de-açúcar e a aplicação no solo de resíduos como vinhaça e torta de filtro podem promover melhorias no sistema produtivo da cultura. Assim, este trabalho objetivou avaliar as alterações nos atributos químicos, no estoque de carbono orgânico total e das frações humificadas da matéria orgânica de um Latossolo Vermelho cultivado com cana-de-açúcar com os seguintes sistemas de manejo: cana crua com aplicação de vinhaça (CCV), cana queimada sem aplicação de resíduos (CQS), cana queimada com aplicação de vinhaça (CQV), cana queimada com aplicação de torta de filtro (CQTF) e cana queimada com aplicação conjunta de vinhaça e torta de filtro (CQVTF). Como referência utilizou-se uma área de vegetação natural (VN), Cerrado sensu stricto. O tratamento CQVTF apresentou melhoria nos atributos químicos do solo, aumentou os estoques de carbono orgânico total COT (valores variando de 21,28 a 40,02 Mg ha-1) e das frações humificadas da matéria orgânica do solo em relação aos demais tratamentos. A área com CQS, na profundidade de 0-0,05 m, apresentou as maiores perdas de estoques de COT do solo (56,3 %) em relação à VN. A adoção do manejo CCV apresentou atributos químicos e estoques de COT do solo equivalentes aos observados nas áreas com CQV e CQTF apesar do curto período de adoção (3 anos). Os teores de COT correlacionaram-se com a soma...(AU)

Chemical attributes, total organic carbon stock and humified fractions of organic matter soil submitted to different systems of sugarcane management / Atributos químicos, estoque de carbono orgânico total e das frações humificadas da matéria orgânica do solo em diferentes sistemas de manejo de cana-de-açúcar

Mechanized harvesting maintenance of trash from cane sugar and soil application of waste as vinasse and filter cake can improve the system of crop yield. Thus, this study aimed to evaluate the changes in the chemical, the stock of total organic carbon and humified organic matter fractions in an Oxisol cultivated with cane sugar with the following management systems: with sugarcane vinasse application (CCV), without application of burnt cane waste (CQS), with burnt cane vinasse application (CQV), with application of burnt cane filter cake (CQTF) and burnt cane with joint application of vinasse and filter cake (CQVTF). For reference we used an area of natural vegetation (NV), Cerrado sensu stricto. Treatment CQVTF showed improvement in soil chemical properties, increased inventory levels of total organic carbon TOC (values ranging from 21.28 to 40.02 Mg ha-1) and humified fractions of soil organic matter in relation to other treatments. The CQS area at a depth of 0-0.05 m, showed the greatest losses of soil TOC stocks (56.3%) compared to NV. The adoption of management presented CCV and chemical attributes of the soil TOC stocks equivalent to those observed in areas with CQV CQTF and despite the short period of adoption (3 years). The TOC correlated with the sum of bases (r = 0.76 **), cation exchange capacity (r = 0.59 **) and base saturation (r = 0.63 **), while the humic acids...

A colheita mecanizada com manutenção do palhiço da cana-de-açúcar e a aplicação no solo de resíduos como vinhaça e torta de filtro podem promover melhorias no sistema produtivo da cultura. Assim, este trabalho objetivou avaliar as alterações nos atributos químicos, no estoque de carbono orgânico total e das frações humificadas da matéria orgânica de um Latossolo Vermelho cultivado com cana-de-açúcar com os seguintes sistemas de manejo: cana crua com aplicação de vinhaça (CCV), cana queimada sem aplicação de resíduos (CQS), cana queimada com aplicação de vinhaça (CQV), cana queimada com aplicação de torta de filtro (CQTF) e cana queimada com aplicação conjunta de vinhaça e torta de filtro (CQVTF). Como referência utilizou-se uma área de vegetação natural (VN), Cerrado sensu stricto. O tratamento CQVTF apresentou melhoria nos atributos químicos do solo, aumentou os estoques de carbono orgânico total COT (valores variando de 21,28 a 40,02 Mg ha-1) e das frações humificadas da matéria orgânica do solo em relação aos demais tratamentos. A área com CQS, na profundidade de 0-0,05 m, apresentou as maiores perdas de estoques de COT do solo (56,3 %) em relação à VN. A adoção do manejo CCV apresentou atributos químicos e estoques de COT do solo equivalentes aos observados nas áreas com CQV e CQTF apesar do curto período de adoção (3 anos). Os teores de COT correlacionaram-se com a soma...

Bioconversion of petroleum hydrocarbons in soil using apple filter cake / Bioconversão de hidrocarbonetos de petróleo no solo pelo uso de bagaço de maçã

The aim of this study was to investigate the feasibility of using apple filter cake, a fruit-processing waste to enhance the bioremediation of petroleum contaminated soil. A rotating barrel system was used to study the bioconversion of the xenobiotic compound by natural occurring microbial population. The soil had been accidentally polluted with a total petroleum hydrocarbon concentration of 41,000 ppm. Although this global value was maintained during the process, microbial intervention was evidenced through transformation of the petroleum fractions. Thus, fractions that represent a risk for the environment (GRO, Gasoline Range Organics i.e., C6 to C10-12; DRO, Diesel Range Organics i.e., C8-12 to C24-26 and RRO, Residual Range Organics i.e., C25 to C35) were significantly reduced, from 2.95 percent to 1.39 percent. On the contrary, heavier weight fraction from C35 plus other organics increased in value from 1.15 percent to 3.00 percent. The noticeable diminution of low molecular weight hydrocarbons content and hence environmental risk by the process plus the improvement of the physical characteristics of the soil, are promising results with regard to future application at large scale.

O objetivo deste estudo foi investigara viabilidade de aplicação de bagaço de maçã, um resíduo do processamento de frutas, para melhorar a biorremediação de solo contaminado com petróleo. Para estudar a bioconversão de compostos xenobióticos pela população microbiana naturalmente presente empregou-se um sistema de barril rotativo. O solo havia sido acidentalmente contaminado com um total de hidrocarbonetos de petróleo na concentração de 41.000 ppm. Embora esse valor tenha se mantido durante o processo, a intervenção microbiana ficou evidenciada através da transformação de frações do petróleo. Assim, as frações de risco para o meio ambiente (GRO, Gasoline Range Organics, i.e., C6 a C10-12; DRO, Diesel Ramge Organics, i.e. C8-12 a C24-26 e RRO, Residual Range Organics, i.e. C25 a C35) foram significativamente reduzidas de 2,95 por cento para 1,39 por cento. Por outro lado, frações mais pesadas, acima de C35, e outros compostos orgânicos aumentaram de 1,15 por cento para 3,00 por cento. A diminuição notável do conteúdo de hidrocarbonetos de baixo peso molecular e conseqüentemente do risco ambiental por esse processo, além da melhoria das características físicas do solo, são resultados promissores para uma futura aplicação em grande escala.

Bioconversion of petroleum hydrocarbons in soil using apple filter cake.

The aim of this study was to investigate the feasibility of using apple filter cake, a fruit-processing waste to enhance the bioremediation of petroleum contaminated soil. A rotating barrel system was used to study the bioconversion of the xenobiotic compound by natural occurring microbial population. The soil had been accidentally polluted with a total petroleum hydrocarbon concentration of 41,000 ppm. Although this global value was maintained during the process, microbial intervention was evidenced through transformation of the petroleum fractions. Thus, fractions that represent a risk for the environment (GRO, Gasoline Range Organics i.e., C6 to C10-12; DRO, Diesel Range Organics i.e., C8-12 to C24-26 and RRO, Residual Range Organics i.e., C25 to C35) were significantly reduced, from 2.95% to 1.39%. On the contrary, heavier weight fraction from C35 plus other organics increased in value from 1.15% to 3.00%. The noticeable diminution of low molecular weight hydrocarbons content and hence environmental risk by the process plus the improvement of the physical characteristics of the soil, are promising results with regard to future application at large scale.

Bioconversion of petroleum hydrocarbons in soil using apple filter cake

The aim of this study was to investigate the feasibility of using apple filter cake, a fruit-processing waste to enhance the bioremediation of petroleum contaminated soil. A rotating barrel system was used to study the bioconversion of the xenobiotic compound by natural occurring microbial population. The soil had been accidentally polluted with a total petroleum hydrocarbon concentration of 41,000 ppm. Although this global value was maintained during the process, microbial intervention was evidenced through transformation of the petroleum fractions. Thus, fractions that represent a risk for the environment (GRO, Gasoline Range Organics i.e., C6 to C10-12; DRO, Diesel Range Organics i.e., C8-12 to C24-26 and RRO, Residual Range Organics i.e., C25 to C35) were significantly reduced, from 2.95% to 1.39%. On the contrary, heavier weight fraction from C35 plus other organics increased in value from 1.15% to 3.00%. The noticeable diminution of low molecular weight hydrocarbons content and hence environmental risk by the process plus the improvement of the physical characteristics of the soil, are promising results with regard to future application at large scale.

O objetivo deste estudo foi investigara viabilidade de aplicação de bagaço de maçã, um resíduo do processamento de frutas, para melhorar a biorremediação de solo contaminado com petróleo. Para estudar a bioconversão de compostos xenobióticos pela população microbiana naturalmente presente empregou-se um sistema de barril rotativo. O solo havia sido acidentalmente contaminado com um total de hidrocarbonetos de petróleo na concentração de 41.000 ppm. Embora esse valor tenha se mantido durante o processo, a intervenção microbiana ficou evidenciada através da transformação de frações do petróleo. Assim, as frações de risco para o meio ambiente (GRO, Gasoline Range Organics, i.e., C6 a C10-12; DRO, Diesel Ramge Organics, i.e. C8-12 a C24-26 e RRO, Residual Range Organics, i.e. C25 a C35) foram significativamente reduzidas de 2,95% para 1,39%. Por outro lado, frações mais pesadas, acima de C35, e outros compostos orgânicos aumentaram de 1,15% para 3,00%. A diminuição notável do conteúdo de hidrocarbonetos de baixo peso molecular e conseqüentemente do risco ambiental por esse processo, além da melhoria das características físicas do solo, são resultados promissores para uma futura aplicação em grande escala.

Apparent digestibility of rations with different levels of filter cake from sugar mill industries in lambs (Ovis aries L.) / Digestibilidade (aparente) de rações com diferentes níveis de torta de filtro de usina açucareira com ovinos (Ovis aries L.)

An experiment was conducted with 12 crossbreed wether in a completely randomized design to evaluate rations with different levels of filter cake and Coast Cross hay (Cynodon dactylon). The sheep received the experimental diets for 21 days, and in the last seven, total faeces and urine collections were made. Isoproteic and isoenergetic diets contained filter cake and Coast Cross hay as follow: A - 20% cake and 80% hay; B - 40% cake and 60% hay; C - 60% cake and 40% hay; D - 80% cake and 20% hay. Dry matter, crude protein, crude fiber and nitrogen-free extract intake decreased linearly (p 0.05) with increasing levels of filter cake. Except to nitrogen-free extract, apparent digestibilities of dry matter, crude protein, crude fiber, ether extract and TDN values were not affected by filter cake addition to the diets.

Doze carneiros adultos, com peso médio de 43 kg, foram utilizados num delineamento inteiramente casualizado, para determinar o valor nutritivo de rações com diferentes níveis da mistura de torta de filtro com feno de Coast Cross (Cynodon dactylon), visando avaliar a torta como alimento presente em rações animais. O período experimental teve duração de 21 dias, sendo a coleta total de fezes e urina realizada nos últimos 7, quando a ingestão foi restringida a 80% do valor obtido ad libitum. Os tratamentos foram as rações seguintes, compostas de torta de filtro e feno de Coast-Cross, balanceadas para serem isoprotéicas e isoenergéticas: A - 20% de torta + 80% de feno; B - 40% de torta e 60% de feno; C - 60% de torta + 40% de feno e D - 80% de torta + 20% de feno. Os resultados mostraram que a ingestão da matéria seca, proteína bruta, fibra bruta, extrativos não nitrogenados diminuiu linearmente (p 0,05) com o aumento da porcentagem de torta de filtro nas rações. Os coeficientes de digestibilidade aparente dos tratamentos foram: Matéria Seca - 27,86%, 41,68%, 31,18% e 33,80%; Proteína Bruta - 43,99%, 38,78%, 36,08% e 35,58%; Fibra Bruta - 31,70%, 47,00%, 33,72% e 35,88%; Extrativo Não Nitrogenado - 31,56%, 48,18%, 44,55% e 48,51%; Extrato Etéreo - 26,63%, 27,49%, 19,48% e 31,18%, sendo os Nutrientes Digestíveis Totais iguais a 31,52%, 43,01%, 34,89% e 38,90% para os tratamentos

Efeito de substrato artificial no enraizamento de estacas de calanchoe (Kalanchoe x blossfeldiana cv. singapur, crassulaceae)

Ten different artificial mixtures were studied as rooting media for Kalanchoe x blossfeldiana cv. Singapur cuttings. They were: vermiculite + toasted rice hulls (1:1, 2:1, 3:1); vermiculite + Oliver filter cake (1:1, 2:1, 3:1); vermiculite + peat (1:1, 2:1, 3:1); and vermiculite + pine bark (commercial mixture). The best results were observed for vermiculite + Oliver filter cake (1:1, 2:1, 3:1), vermiculite + toasted rice hulls (3:1) and vermiculite + peat (3:1). The worst results were observed with vermiculite + pine bark and vermiculite + peat (1:1).

Dez misturas artificiais foram estudadas para avaliar o efeito sobre o enraizamento de estacas apicais de Kalanchoe x blossfeldiana cv. Singapur, da família Crassulaceae. Essas misturas foram as seguintes: vermiculita + casca de arroz tostada nas proporções 1:1, 2:1 e 3:1; vermiculita + torta de filtro Oliver nas proporções 1:1, 2:1 e 3:1; vermiculita + turfa da região de Atibaia-SP, nas proporções 1:l, 2:le3:l; vermiculita + casca de pinheiro (mistura comercial). Os melhores resultados foram obtidos com a mistura vermiculita + torta de filtro Oliver em todas as proporções, vermiculita + casca de arroz tostada 3:1 e vermiculita + turfa 3:1. Os piores desempenhos foram os das misturas vermiculita + casca de pinheiro e vermiculita + turfa 1:1.

Efeito de substrato artificial no enraizamento de estacas de calanchoe (Kalanchoe x blossfeldiana cv. singapur, crassulaceae)

Ten different artificial mixtures were studied as rooting media for Kalanchoe x blossfeldiana cv. Singapur cuttings. They were: vermiculite + toasted rice hulls (1:1, 2:1, 3:1); vermiculite + Oliver filter cake (1:1, 2:1, 3:1); vermiculite + peat (1:1, 2:1, 3:1); and vermiculite + pine bark (commercial mixture). The best results were observed for vermiculite + Oliver filter cake (1:1, 2:1, 3:1), vermiculite + toasted rice hulls (3:1) and vermiculite + peat (3:1). The worst results were observed with vermiculite + pine bark and vermiculite + peat (1:1).

Dez misturas artificiais foram estudadas para avaliar o efeito sobre o enraizamento de estacas apicais de Kalanchoe x blossfeldiana cv. Singapur, da família Crassulaceae. Essas misturas foram as seguintes: vermiculita + casca de arroz tostada nas proporções 1:1, 2:1 e 3:1; vermiculita + torta de filtro Oliver nas proporções 1:1, 2:1 e 3:1; vermiculita + turfa da região de Atibaia-SP, nas proporções 1:l, 2:le3:l; vermiculita + casca de pinheiro (mistura comercial). Os melhores resultados foram obtidos com a mistura vermiculita + torta de filtro Oliver em todas as proporções, vermiculita + casca de arroz tostada 3:1 e vermiculita + turfa 3:1. Os piores desempenhos foram os das misturas vermiculita + casca de pinheiro e vermiculita + turfa 1:1.