Effective remediation of fish processing waste using mixed culture biofilms capable of simultaneous nitrification and denitrification.

Fish processing waste water causes pollution and eutrophication of water bodies when released untreated. Use of bacteria capable of simultaneous nitrification and denitrification (SND) as biofilms on carriers in a moving bed bioreactor (MBBR) is a popular approach but seldom used for fish processing waste water remediation. Here, we studied the variations in biofilm formation and application activities by isolates Lysinibacillus sp. HT13, Alcaligenes sp. HT15 and Proteus sp. HT37 previously reported by us. While HT13 and HT15 formed significantly higher biofilms in polystyrene microtitre plates than on carriers, HT37 exhibited highest on carriers. A consortium of the three selected bacteria grown as biofilm on MBBR carriers exhibited better remediation of ammonia (200-600 ppm and 50 mM) than the individual isolates on carriers. The mixed biofilm set on the carriers was used for nitrogenous waste removal from fish processing waste water in 2 and 20 L setups. The total nitrogen estimated by elemental analysis showed complete remediation from 250 ppm in both 2 and 20 L waste water systems within 48 h. The usual toxic nitrogenous components-ammonia, nitrite and nitrate were also remediated efficiently.

Effect of intrauterine marijuana exposure on fetal growth patterns and placental vascular resistance.

OBJECTIVE: The recent legalization of marijuana has increased overall use, including in pregnancy. Studies have previously associated marijuana use with adverse fetal neurodevelopmental outcomes. We sought to compare fetal sonographic growth parameters and placental perfusion, as measured by umbilical artery Dopplers, in women using daily marijuana versus nonusers. METHODS: A retrospective cohort study capturing self - identified pregnant daily marijuana users with gestational aged matched controls was performed. We compared maternal demographics, fetal biometry, nuchal translucency, and umbilical artery Dopplers in marijuana users versus controls. Intrauterine growth restriction was defined as an estimated fetal weight <10th %. RESULTS: In 55 first trimester ultrasounds, there were no differences in crown rump lengths or nuchal translucencies between the groups. Likewise, in 195-second trimester ultrasounds, no differences were noted in biometry. Second trimester umbilical artery systolic to diastolic ratios were higher in marijuana users compared to nonusers (4.02 versus 3.92, p = .024). In the third trimester, 26 of 192 marijuana exposed fetuses were growth restricted compared to 6 of 192 controls (p = .002), and umbilical artery systolic to diastolic ratios were higher (3.52 versus 3.12, p = .0001). Four cases of absent and reversed end diastolic flow were observed in marijuana users, while no cases were observed in controls. CONCLUSIONS: Our data shows that daily marijuana use is associated with impaired fetal growth and increased placental vascular resistance. Marijuana consumption in pregnancy should be avoided until further studies delineate its exact potential for fetotoxicity.