Journal: International Microbiology

Article Title: Inoculation methods that enhance the survival of Bacillus strains in rice husk biochar for use as bacterial carriers

doi: 10.1007/s10123-025-00737-5

Figure Lengend Snippet: Survival of eight type strains of Bacillus species in rice husk biochar. A bacterial suspension was obtained by pre-culturing bacteria on a nutrient agar plate for 1 day ( a , b ), 2 days ( c , d ), or 7 days ( e , f ), followed by suspension in sterile water. Each inoculum was either nonheat-treated (NHT) ( a , c , and e ) or heat-treated (HT) at 80 °C for 1 h ( b , d , and f ) and inoculated onto biochar. The day of bacterial inoculation was designated day 0. The bacterial density in the biochar was determined after incubation at 28 °C for 7 days ( n = 3). N.D. indicates no detection. Error bar indicates standard error. Asterisks indicate significant difference ( P < 0.05) between 0 and 7 days according to t -test, and n.s. indicates no significant difference

Article Snippet: The stock culture of Bacillus type strains was streaked onto a nutrient agar (NA) plate (Nutrient broth [BD Difco] supplemented with 1.5% agar) and cultured at 28 °C.

Techniques: Suspension, Bacteria, Sterility, Incubation

Journal: International Microbiology

Article Title: Inoculation methods that enhance the survival of Bacillus strains in rice husk biochar for use as bacterial carriers

doi: 10.1007/s10123-025-00737-5

Figure Lengend Snippet: Effects of biochar washing on bacterial survival of eight type strains of Bacillus species. A bacterial suspension was obtained by pre-culturing bacteria in a nutrient agar plate for 1 day. The bacterial density in the inoculum of nonheat-treated (NHT) and heat-treated (HT) suspensions was determined in advance. The NHT bacterial suspension was inoculated onto unwashed biochar ( a ) or biochar after washing with reverse osmosis water ( b ). The day of bacterial inoculation was designated day 0. Survival rates ( c ) were calculated using the following formula: survival rate (%) = ( A / B ) × 100, where A is the bacterial density at 7 days and B is the bacterial density under NHT conditions at day 0. The bacterial density in the biochar was determined after incubation at 28 °C for 7 days ( n = 3). N.D. indicates no detection. Error bar indicates standard error. Survival rates were arcsine-transformed before performing statistical tests. Different letters indicate significant differences ( P < 0.05) according to the Tukey–Kramer test. Asterisks indicate significant difference ( P < 0.05) between unwashed and washed biochar according to t -test, and n.s. indicates no significant difference

Article Snippet: The stock culture of Bacillus type strains was streaked onto a nutrient agar (NA) plate (Nutrient broth [BD Difco] supplemented with 1.5% agar) and cultured at 28 °C.

Techniques: Suspension, Bacteria, Incubation, Transformation Assay

Journal: International Microbiology

Article Title: Inoculation methods that enhance the survival of Bacillus strains in rice husk biochar for use as bacterial carriers

doi: 10.1007/s10123-025-00737-5

Figure Lengend Snippet: Survival of eight type strains of Bacillus strains in biochar water extract. A bacterial suspension was obtained by pre-culturing bacteria in a nutrient agar plate for 1 day ( a – g ) or 7 days (i–p), followed by suspension in sterile water. The bacterial density in the inoculum of nonheat-treated (NHT) and heat-treated (HT) suspensions was determined in advance. The NHT bacterial suspension was inoculated in sterile water (W1, pH 6.7), high-pH sterile water (W2, pH 10.2), and biochar water extracts (biochar: water [w/v] = 0.5:10 [Ex1, pH 9.8] or 1:10 [Ex2, pH 10.2]). The day of bacterial inoculation was designated day 0. The bacterial density in the biochar was determined after incubation at 28 °C for 7 days ( n = 3). B. velezensis LMG 22478 T ( a , i ); B. amyloliquefaciens NBRC 15535 T ( b , j ); B. nakamurai CCUG 68786 T ( c , k ); B. siamensis LMG 27549 T ( d , l ); B. subtilis NBRC 13719 T ( e , m ); B. pumilus NBRC 12092 T ( f , n ); B. licheniformis NBRC 12200 T ( g , o ); and B. thuringiensis NBRC 101235 T ( h , p ). N.D. indicates no detection. Error bar indicates standard error. Different letters indicate significant differences ( P < 0.05) according to the Tukey–Kramer test

Article Snippet: The stock culture of Bacillus type strains was streaked onto a nutrient agar (NA) plate (Nutrient broth [BD Difco] supplemented with 1.5% agar) and cultured at 28 °C.

Techniques: Suspension, Bacteria, Sterility, Incubation

Journal: International Microbiology

Article Title: Inoculation methods that enhance the survival of Bacillus strains in rice husk biochar for use as bacterial carriers

doi: 10.1007/s10123-025-00737-5

Figure Lengend Snippet: Long-term changes in bacterial density ( a ) and survival rate ( b ) of eight type strains of Bacillus strain in biochar. A bacterial suspension was obtained by pre-culturing bacteria in a nutrient agar plate for over 7 days, followed by suspension in sterile water. The bacterial density in the inoculum of nonheat-treated (NHT) and heat-treated (HT) suspensions was determined in advance. The HT bacterial suspension was inoculated onto unwashed biochar. The day of bacterial inoculation was designated day 0. The bacterial density in the biochar was determined after incubation at 25 °C for 2, 5, and 12 weeks ( n = 6). Survival rates were calculated using the following formula: survival rate (%) = ( A / B ) × 100, where A is the bacterial density at 2, 5, or 12 weeks and B is the bacterial density under NHT conditions at day 0. Error bar indicates standard error. Asterisks indicate significant differences ( P < 0.05) from bacterial densities of NHT inoculation at day 0 in each Bacillus strain according to Dunnett’s test. Effect modifications ( P < 0.001) in among Bacillus species, periods, and combination of Bacillus species and periods in bacterial densities in the biochar were detected by two-way ANOVA

Article Snippet: The stock culture of Bacillus type strains was streaked onto a nutrient agar (NA) plate (Nutrient broth [BD Difco] supplemented with 1.5% agar) and cultured at 28 °C.

Techniques: Suspension, Bacteria, Sterility, Incubation