{"title":"用人类粪便和尿液制成的生物肥料改良粉壤土中肠道细菌和病毒的命运","authors":"Priscila Carlon , Fernanda Daniela Gonçalves Ferreira , Cacea Furlan Maggi Carloto , Gislaine Fongaro , Maria Elisa Magri","doi":"10.1016/j.heha.2023.100067","DOIUrl":null,"url":null,"abstract":"<div><p>Human excreta can be used as biofertilizers due to their nutrient and organic matter content. Nevertheless, the behavior of microorganisms should be investigated, as enteric pathogens can accumulate in the soil. Therefore, we evaluated the survival and transport of two enteric bacteria (<em>E. coli</em> and <em>Salmonella enterica</em>) and two enteric virus surrogates (MS2 and ΦX-174 bacteriophages) when applied as contaminants of four biofertilizers on <em>Lactuca sativa</em> production. The study was carried out in lysimeters outdoors with repacked silt loam soil, using a randomized block design (RBD) with six treatments and three replicates. Biofertilizers were urea-treated feces, feces composted with organic waste, stored liquid urine, and struvite and were inoculated at 10<sup>6</sup>–10<sup>7</sup> cfu/pfu g<sup>−1</sup> of <em>E. coli</em> and bacteriophages strains and 10<sup>7</sup>–10<sup>9</sup> of <em>S. enterica</em>. Soil amended with composted feces exhibited the lowest decimal reductions (T<sub>90</sub>) for the microorganisms evaluated, with 10.2 days for <em>E. coli</em>, 11.9 days for <em>S. enterica</em>, 22.2 days for MS2, and 3.7 days for ΦX-174. Urea-treated feces temporarily hindered the growth and survival of <em>E. coli</em> and <em>S. enterica</em> in the soil. However, both bacteria were present after one month, while MS2 showed a stable concentration with this biofertilizer. <em>E. coli</em> presented a stable behavior when applied with urine, whereas MS2 was stable with urea-treated feces, urine, and struvite. ΦX-174 and <em>S. enterica</em> were not considered good representatives of most resistant enteric pathogens’ behavior in the soil during food production since they were not detected in leachate and showed a rapid die-off in soil. <em>E. coli</em> leached faster and in higher concentrations than MS2, which presented higher concentrations in deeper soil layers, from 10 to 20 cm. Therefore, using urine, struvite, and urea-treated faces implied a higher chance of infection, as a decimal reduction time was not observed during the 36 days of the experiment. As a result, in short-term cultures, it is recommended that additional hygiene barriers are taken to avoid infection since <em>E. coli</em> and MS2 were still detected at the end of the experiment. An interval of 90 days between fertilizing and harvesting is recommended to prevent pathogen infection. These results are the basis for a quantitative risk assessment of human excreta-based biofertilizers for food production.</p></div>","PeriodicalId":73269,"journal":{"name":"Hygiene and environmental health advances","volume":"7 ","pages":"Article 100067"},"PeriodicalIF":0.0000,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Fate of enteric bacteria and viruses in silt loam soil amended with biofertilizers made from human feces and urine for crop production\",\"authors\":\"Priscila Carlon , Fernanda Daniela Gonçalves Ferreira , Cacea Furlan Maggi Carloto , Gislaine Fongaro , Maria Elisa Magri\",\"doi\":\"10.1016/j.heha.2023.100067\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Human excreta can be used as biofertilizers due to their nutrient and organic matter content. Nevertheless, the behavior of microorganisms should be investigated, as enteric pathogens can accumulate in the soil. Therefore, we evaluated the survival and transport of two enteric bacteria (<em>E. coli</em> and <em>Salmonella enterica</em>) and two enteric virus surrogates (MS2 and ΦX-174 bacteriophages) when applied as contaminants of four biofertilizers on <em>Lactuca sativa</em> production. The study was carried out in lysimeters outdoors with repacked silt loam soil, using a randomized block design (RBD) with six treatments and three replicates. Biofertilizers were urea-treated feces, feces composted with organic waste, stored liquid urine, and struvite and were inoculated at 10<sup>6</sup>–10<sup>7</sup> cfu/pfu g<sup>−1</sup> of <em>E. coli</em> and bacteriophages strains and 10<sup>7</sup>–10<sup>9</sup> of <em>S. enterica</em>. Soil amended with composted feces exhibited the lowest decimal reductions (T<sub>90</sub>) for the microorganisms evaluated, with 10.2 days for <em>E. coli</em>, 11.9 days for <em>S. enterica</em>, 22.2 days for MS2, and 3.7 days for ΦX-174. Urea-treated feces temporarily hindered the growth and survival of <em>E. coli</em> and <em>S. enterica</em> in the soil. However, both bacteria were present after one month, while MS2 showed a stable concentration with this biofertilizer. <em>E. coli</em> presented a stable behavior when applied with urine, whereas MS2 was stable with urea-treated feces, urine, and struvite. ΦX-174 and <em>S. enterica</em> were not considered good representatives of most resistant enteric pathogens’ behavior in the soil during food production since they were not detected in leachate and showed a rapid die-off in soil. <em>E. coli</em> leached faster and in higher concentrations than MS2, which presented higher concentrations in deeper soil layers, from 10 to 20 cm. Therefore, using urine, struvite, and urea-treated faces implied a higher chance of infection, as a decimal reduction time was not observed during the 36 days of the experiment. As a result, in short-term cultures, it is recommended that additional hygiene barriers are taken to avoid infection since <em>E. coli</em> and MS2 were still detected at the end of the experiment. An interval of 90 days between fertilizing and harvesting is recommended to prevent pathogen infection. These results are the basis for a quantitative risk assessment of human excreta-based biofertilizers for food production.</p></div>\",\"PeriodicalId\":73269,\"journal\":{\"name\":\"Hygiene and environmental health advances\",\"volume\":\"7 \",\"pages\":\"Article 100067\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Hygiene and environmental health advances\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2773049223000235\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Hygiene and environmental health advances","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2773049223000235","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Fate of enteric bacteria and viruses in silt loam soil amended with biofertilizers made from human feces and urine for crop production
Human excreta can be used as biofertilizers due to their nutrient and organic matter content. Nevertheless, the behavior of microorganisms should be investigated, as enteric pathogens can accumulate in the soil. Therefore, we evaluated the survival and transport of two enteric bacteria (E. coli and Salmonella enterica) and two enteric virus surrogates (MS2 and ΦX-174 bacteriophages) when applied as contaminants of four biofertilizers on Lactuca sativa production. The study was carried out in lysimeters outdoors with repacked silt loam soil, using a randomized block design (RBD) with six treatments and three replicates. Biofertilizers were urea-treated feces, feces composted with organic waste, stored liquid urine, and struvite and were inoculated at 106–107 cfu/pfu g−1 of E. coli and bacteriophages strains and 107–109 of S. enterica. Soil amended with composted feces exhibited the lowest decimal reductions (T90) for the microorganisms evaluated, with 10.2 days for E. coli, 11.9 days for S. enterica, 22.2 days for MS2, and 3.7 days for ΦX-174. Urea-treated feces temporarily hindered the growth and survival of E. coli and S. enterica in the soil. However, both bacteria were present after one month, while MS2 showed a stable concentration with this biofertilizer. E. coli presented a stable behavior when applied with urine, whereas MS2 was stable with urea-treated feces, urine, and struvite. ΦX-174 and S. enterica were not considered good representatives of most resistant enteric pathogens’ behavior in the soil during food production since they were not detected in leachate and showed a rapid die-off in soil. E. coli leached faster and in higher concentrations than MS2, which presented higher concentrations in deeper soil layers, from 10 to 20 cm. Therefore, using urine, struvite, and urea-treated faces implied a higher chance of infection, as a decimal reduction time was not observed during the 36 days of the experiment. As a result, in short-term cultures, it is recommended that additional hygiene barriers are taken to avoid infection since E. coli and MS2 were still detected at the end of the experiment. An interval of 90 days between fertilizing and harvesting is recommended to prevent pathogen infection. These results are the basis for a quantitative risk assessment of human excreta-based biofertilizers for food production.