A preliminary metagenomics study of bacteria present in the dirt of Swiftlet farmhouses based on nitrite levels in edible bird's nest on Sumatera Island, Indonesia.

Background and Aim: Since the past decade, metagenomics has been used to evaluate sequenced deoxyribonucleic acid of all microorganisms in several types of research. Nitrite contamination originates from the natural environment in Swiftlet farmhouses (SFHs) and can influence nitrite levels in edible bird's nest (EBN). It is strongly speculated that the conversion process into nitrite is influenced by the bacteria present in SFHs. Nitrite can cause adverse effects on human health. The previous research has focused on the characteristics of bacteria that may influence the nitrite conversion process in SFHs. This study aimed to a metagenomics analysis of bacteria present in the dirt of SFHs and evaluated nitrite levels in EBN on Sumatera Island. Materials and Methods: In total, 18 SFHs on Sumatera Island were selected, and EBN and dirt samples were collected from each SFH, resulting in 18 EBN and 18 dirt SFH samples. Raw uncleaned white EBN and dirt from three areas of SFH were collected. The samples were analyzed for nitrite levels using a spectrophotometer, and the metagenomics sequencing of SFH dirt samples was performed using the MinIon nanopore method. The sequenced data were analyzed using the EPI2ME software. Results: Of the 18 raw uncleaned white EBN samples, 9 (50%) had <30 ppm nitrite levels. The top five bacterial genera in SFH dirt samples in Group A (nitrite levels >30 ppm) were Aeromonas, Escherichia, Acinetobacter, Arcobacter, and Acetoanaerobium. Those in Group B (nitrite levels <30 ppm) were Aeromonas, Pseudomonas, Shewanella, Escherichia, and Acinetobacter. There were 12 genera of nitrifying bacteria in Group A and 8 in Group B. The total cumulative read of nitrifying bacteria in Groups A and B were 87 and 38 reads, respectively. Conclusion: This is the first study to show that characteristic bacteria present in the dirt of SFHs might significantly influence the conversion from nitrogen to nitrite. Approximately 50% of raw uncleaned EBN samples had <30 ppm nitrite levels. Aeromonas was the most dominant bacterial genus found in Groups A and B. The variations in genus and cumulative reads nitrifying bacteria in group A were greater than those in Group B. This study provides information on the characteristics of bacteria that may influence the nitrite conversion process in SFHs. Metagenomics data were obtained from the reading using the software EPI2ME. Further research is needed on the bacterial target species that can convert nitrite in SFHs.

An investigation of heavy metals in edible bird's nest from Indonesia using inductively coupled plasma mass spectrometry.

Background and Aim: In 2020, Indonesia, which has the highest global production of edible bird's nest (EBNs), exported up to 1312.5 tons of this product at a value of USD 540.4 million. Recently, food safety aspects related to EBNs, including contamination with heavy metals, have become a serious concern. However, data on the presence and concentration of heavy metals in EBNs in Indonesia are not yet available. This study aimed to determine and compare the presence and concentrations of arsenic (As), mercury (Hg), lead (Pb), cadmium (Cd), and tin (Sn) in EBNs originating from several primary Indonesian islands. The study also analyzed the effect of washing on the heavy metal content in EBNs. Materials and Methods: A study on 44 swiftlet farmhouses (SFHs) was conducted to determine the concentrations of heavy metals in EBNs. The number of samples from the SFHs was allocated proportionally to the main EBN-producing islands in Indonesia, that is, Kalimantan, Sumatera, Sulawesi, and Java (22, 13, 7, and 2, respectively). The concentrations of the above five elements in the samples before washing (raw-unclean EBNs) and after washing (raw-clean EBNs) were determined by inductively coupled plasma mass spectrometry. Washing was conducted according to the general procedures at an EBN processing plant. Results: The raw-unclean EBNs from the four islands contained As, Pb, Cd, and Sn at varying concentrations. However, Hg was not detected in the raw-unclean EBN samples from Sulawesi. The raw-unclean EBNs from Kalimantan had lower concentrations of Pb and Cd compared with the other islands. The concentrations of As, Pb, Cd, and Sn in the EBNs decreased significantly after washing with clean water. Conclusion: Heavy metals (As, Hg, Pb, Cd, and Sn) were detected at a low level in most of the raw-unclean EBNs originating from the main Indonesian island where they were produced. The concentrations of all the heavy metals reviewed in the raw-unclean EBNs samples decreased significantly after washing.

Chemical compositions, contaminants, and residues of organic and conventional goat milk in Bogor District, Indonesia.

AIM: This study aimed to compare chemical composition and contaminants (pesticide residues, antibiotic residues, and heavy metal residues) between organic and conventional goat milk in Bogor District, West Java Province, Indonesia. MATERIALS AND METHODS: Milk sampling was carried out from March to August 2018 at six goat farms. The chemical quality of milk was checked using the Lactoscan Ultrasonic Milk Analyzer device. Fatty acids were analyzed using gas chromatography (GC). Pesticide residues in goat's milk were analyzed using a GC-electron capture detector (GC-ECD). Antibiotic residues were analyzed using bioassay screening test method. The lead (Pb) and arsenic (As) residues were analyzed using the Atomic Absorption Spectrophotometer (AAS). RESULTS: The content of fat, protein, and lactose showed that there was no difference in the composition of goat's milk between organic and conventional farms. Caprylic acid (C8:0) and capric acid (C10:0) of organic goat milk are higher than conventional goat milk. Stearic acid (C18:0) and linoleic acid (C18:2) of conventional goat milk are higher than organic goat milk. The total fatty acid of organic goat milk is higher than conventional goat milk. Organochlorine pesticide residues were not detected in organic goat milk and conventional goat milk. Tetracycline antibiotic residues were found in one sample (5.56%) of organic goat milk, and macrolides residues were found in two samples (11.11%) of conventional goat milk. Pb residue in organic goat milk is 50 ppb while conventional goat milk is 80 ppb. Residue As in organic goat milk is 70 ppb while conventional goat milk is 110 ppb. CONCLUSION: There was no chemical composition (fat, protein, and lactose) difference between organic and conventional goat milk. Saturated fatty acid (SFA) in organic goat milk is higher than conventional goat milk. Pesticide residues are not found in both organic and conventional goat milk. Tetracycline antibiotics were found in organic goat milk and macrolide antibiotic groups found in conventional goat milk. Pb and As residues were found in both organic goat milk and conventional goat milk.