scholarly journals Penapisan Bakteri yang Diisolasi dari Tambak Udang sebagai Kandidat Probiotik pada Budi daya Udang Windu, Penaeus monodon

2016 ◽  
Vol 1 (1) ◽  
pp. 73 ◽  
Author(s):  
Muliani Muliani ◽  
Nurbaya Nurbaya ◽  
Muharijadi Atmomarsono
Keyword(s):  
16S Rrna ◽  
Vibrio Vulnificus ◽  
Rrna Gene ◽  
16S Rrna Gene Analysis ◽  
Shrimp Culture ◽  
Shrimp Pond ◽  
Tiger Shrimp ◽  
Growth Of Bacteria

Penelitian ini bertujuan mendapatkan bakteri probiotik untuk budi daya udang windu P. monodon. Penelitian meliputi beberapa tahapan yaitu (1) isolasi bakteri dari tambak udang; (2) uji daya hambat terhadap Vibrio  harveyi; (3) karakterisasi secara fisiologi dan biokimia; (4) pertumbuhan bakteri pada beberapa konsentrasi NaCl; (5) pertumbuhan bakteri pada beberapa tingkat salinitas; (6) uji patogenisitas bakteri terhadap pascalarva udang windu; (7) uji tantang dengan V. harveyi dalam wadah pemeliharaan pascalarva udang windu; dan (8) analisis gen 16S-rRNA bakteri yang diisolasi dari tambak. Sedikitnya 14 isolat dari 2.228 isolat bakteri yang diisolasi dari tambak, potensial dijadikan probiotik pada budi daya udang windu. Sintasan udang windu tertinggi pada perlakuan yang menggunakan isolat BN2067. Isolat BT950 dan BT95 paling potensial menghambat pertumbuhan V. harveyi baik secara In vitro maupun In vivo. Hasil analisis gen 16Sr-RNA menunjukkan bahwa BT950 dan BT951 termasuk dalam kelompok Brevibacillus sp., sedangkan BN2067 termasuk dalam kelompok Vibrio vulnificus CMCP6 chr.This experiment was aimed for finding-out probiotic bacteria on tiger shrimp P. monodon culture. The research included several steps i.e. 1) isolation of bacteria from tiger shrimp pond; 2) inhibition test of  bacteria against V. harveyi; 3) biochemical and physiological characterization; 4) growth of bacteria at different concentration of NaCl; (5) growth of bacteria at different salinities; (6) pathogenicity test of bacteria to tiger shrimp post larvae, (7) challenge test of bacteria against V. harveyi in tiger shrimp culture media; (8) 16S-rRNA gene analysis of  bacteria isolated from shrimp pond. Fourteen isolates of 2,228 isolates of bacteria isolated from tiger shrimp pond were potential for probiotic bacteria on tiger shrimp culture. The highest survival rate of tiger shrimp was obtained from those treated with BN2067 isolate. The potential isolates to inhibit V. harveyi both In vivo and In vitro assay were BT950 and BT951. Based on 16S-rRNA gene analysis, BT950 and BT951 isolates are considered to be Brevibacillus laterosporus, while BN2067 is considered to be Vibrio vulnificus CMCP6 chr.

scholarly journals Handling of Spurious Sequences Affects the Outcome of High-Throughput 16S rRNA Gene Amplicon Profiling

2020 ◽  
Author(s):  
Thomas Clavel ◽  
Sandra Reitmeier ◽  
Thomas CA Hitch ◽  
Nicole Treichel ◽  
Nikolaos Fikas ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Data Processing ◽  
Relative Abundance ◽  
Large Scale ◽  
Peat Soil ◽  
Rrna Gene ◽  
Dnase Treatment

Abstract Background: 16S rRNA gene amplicon sequencing is a very popular approach for studying microbiomes. However, varying standards exist for sample and data processing and some basic concepts, such as the occurrence of spurious sequences, have not been investigated in a comprehensive manner. Methods: Using defined communities of bacteria in vitro and in vivo, we searched for sequences not matching the expected species (i.e., spurious taxa) and determined a minimum threshold of occurrence suitable for robust data analysis. The presence and origin of spurious taxa were investigated via large-scale amplicon queries and gut samples from germfree mice spiked with target mock DNA. We also assessed the effect of varying sequence-filtering stringency on diversity readouts in human fecal and peat soil communities. Our findings are based on data generated in three sequencing facilities and analyzed via both operational taxonomic units (OTUs) and amplicon sequence variants (ASVs) approaches.Results: 16S rRNA gene amplicon data-processing based on OTUs clustering and singleton removal, a commonly used approach that discards any taxa represented by only one sequence across all samples, delivered an average approximately 50% (mock communities) to 80% (gnotobiotic mice) spurious taxa. The fraction of spurious taxa was generally lower based on ASV analysis, but varied depending on the gene region targeted and the barcoding system used. A relative abundance of 0.25% was found as an effective threshold below which the analysis of spurious taxa can be prevented to a large extent in both OTU- and ASV-based analysis approaches. Most spurious taxa (approx. 70%) detected in simplified communities occurred in samples multiplexed in the same sequencing run and were present in only one of ten runs. DNase treatment of gut content from germfree mice partly helped to exclude spurious taxa from the analysis of spiked mock DNA, but was not necessary when applying the 0.25% relative abundance threshold. Using this cut-off improved the reproducibility of analysis, i.e., specifically by reducing variation in richness estimates by 38% compared with singleton filtering in a benchmarking experiment using six human fecal samples across seven sequencing runs. Beta-diversity analyses of human fecal communities was markedly affected by both the filtering strategy and the type of phylogenetic distances used for comparing samples, highlighting the importance of carefully analyzing data before drawing conclusions. Conclusions: Handling of artifact sequences during bioinformatic processing of 16S rRNA gene amplicon data requires careful attention to avoid the generation of misleading findings. Applying a minimum relative abundance threshold between 0.10 and 0.30% is superior to the singleton removal approach, although study-specific analysis strategies may be needed depending on, for instance, the type of samples analyzed and the sequencing depth achieved. Additionally, we propose the concept of effective richness to facilitate the comparison of results across studies.

scholarly journals Screening of probiotics bacteria from coral reef using co-culture method for controlling vibriosis in tiger shrimp (Penaeus monodon) larvae

2015 ◽  
Vol 10 (2) ◽  
pp. 174
Author(s):  
Ade Dwi Sasanti ◽  
Widanarni . ◽  
Sukenda .
Keyword(s):  
Coral Reef ◽  
Survival Rate ◽  
16S Rrna ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Culture Method ◽  
In Vivo Test ◽  
Tiger Shrimp

<p>ABSTRACT</p><p><br />This study was carried out to obtain bacteria isolates from coral reef using co-culture method which potentially inhibit Vibrio harveyi growth. A total of 110 isolates were isolated from Acropora sp., Merulina sp., Hystrix sp., Poecillophora sp., Porites sp., and Haliophora sp., and were screened for their antagonistic activity against V. harveyi in in vitro and in vivo test. Five candidate probiotics (5H1 candidate probiotics isolated from Acropora sp., 11I and 11G isolates isolated from Hystrix sp. and 13B and 13G1 isolates isolated from Poecillophora sp., was able to inhibit growth of V. harveyi MR5339 RFR up to 101‒102 cfu/mL. Two isolates (13B and 13G1) were not pathogenic at concentration 106 cfu/mL bacteria and could increase of survival rate of tiger shrimp (Penaeus monodon) larvae in in vivo test. Survival rate of tiger shrimp larvae that treatment with 13B and 13G1 were 86,67% and 88,33%, and have a significant different with positive control (61,67%). Partial sequencing of 16S-rRNA showed that 13G1 isolate was similar to V. alginolyticus.<br />Keywords: vibriosis, Vibrio harveyi, tiger shrimp, probiotic, coral reef</p><p><br />ABSTRAK</p><p><br />Penelitian ini bertujuan untuk mendapatkan bakteri probiotik asal terumbu karang dengan metode kultur bersama untuk pengendalian penyakit vibriosis pada larva udang windu (Penaeus monodon). Sebanyak 110 isolat berhasil diisolasi dari Acropora sp., Merulina sp., Hystrix sp., Poecillophora sp., Porites sp., dan Heliophora sp. dan dilakukan penapisan untuk melihat aktivitas kemampuannya melawan Vibrio harveyi MR 5339 RfR dalam uji in vitro dan in vivo. Sebanyak 56 isolat menghasilkan daya hambat terhadap V. harveyi MR5339 RfR pada metode kultur bersama. Lima isolat kandidat probiotik (isolate 5H1 diisolasi dari Acropora sp., isolat 11I dan 11G diisolasi dari Hystrix sp., serta isolat 13B dan 13G1 yang diisolasi dari Poecillophora sp.), mampu menekan pertumbuhan V. harveyi MR5339 RfR hingga 101–102 cfu/mL. Kedua isolat (13B dan 13G1) terbukti tidak bersifat patogen pada konsentrasi 106 cfu/mL dan mampu meningkatkan sintasan larva udang windu pada uji in vivo. Nilai sintasan larva pada perlakuan yang diberi kandidat probiotik 13B dan 13G1 berturut-turut adalah 86,67% dan 88,33%, namun berbeda nyata dengan kontrol positif (61,67%). Hasil analisis sekuen sebagian gen 16S-rRNA menunjukkan bahwa isolat 13G1 termasuk spesies V. algynoliticus.<br /><br />Kata kunci: vibriosis, Vibrio harveyi, udang windu, probiotik, terumbu karang</p>

scholarly journals In vitro analysis of the pea chloroplast 16S rRNA gene promoter.

1989 ◽  
Vol 9 (12) ◽  
pp. 5650-5659 ◽  
Author(s):  
E Sun ◽  
B W Wu ◽  
K K Tewari
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Topoisomerase I ◽  
Transcriptional Start Site ◽  
Gene Promoter ◽  
In Vitro Transcription ◽  
Rrna Gene ◽  
Start Site

A cloned pea chloroplast 16S rRNA gene promoter has been characterized in detail by use of a homologous in vitro transcription system that contains a highly purified chloroplast RNA polymerase. The in vivo and in vitro 16S rRNA transcriptional start site has been identified to be a T on the plus strand, 158 bases upstream of the mature 5' end of the gene. BAL 31 deletions of the 16S rRNA leader region demonstrated that the bases between -66 to +30 relative to the transcriptional start site (+1) are necessary for specific 16S transcription. Disruption of canonical TTGACA or TATAAT elements within this region caused complete transcriptional inactivation and prevented protein binding. The topological requirement for 16S transcription was examined by using a construct that synthesized a transcript from the 16S promoter and released it from a pea plastid putative terminator sequence. This minigene was relaxed in vitro with a topoisomerase I from pea chloroplast. It was shown that the 16S promoter was most active when the minigene plasmid was supercoiled.

scholarly journals Handling of spurious sequences affects the outcome of high-throughput 16S rRNA gene amplicon profiling

2020 ◽  
Author(s):  
Sandra Reitmeier ◽  
Thomas CA Hitch ◽  
Nikolaos Fikas ◽  
Bela Hausmann ◽  
Amanda E Ramer-Tait ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Data Processing ◽  
Relative Abundance ◽  
Large Scale ◽  
Peat Soil ◽  
Rrna Gene ◽  
The Impact

Abstract Background: 16S rRNA gene amplicon sequencing is a very popular approach for studying microbiomes. However, varying standards exist for sample and data processing and some basic concepts such as the occurrence of spurious sequences have not been investigated in a comprehensive manner, which was done in the present study. Methods: Using defined communities of bacteria in vitro and in vivo , we searched for sequences not matching the expected species ( i.e. , spurious taxa) and determine a threshold of occurrence relevant for adequate data analysis. The origin of spurious taxa was then investigated via large-scale amplicon queries. We also assessed the impact of varying sequence filtering stringency on diversity readouts in human fecal and peat soil communities. Results: 16S rRNA gene amplicon data processing based on Operational Taxonomic Units (OTUs) clustering and singleton removal, a commonly used approach that discards any taxa represented by only one sequence across all samples, delivered approx. 50% (mock communities) to 80% (gnotobiotic mice) spurious taxa on average. This spurious fraction of taxa was lower based on amplicon sequence variants (ASVs) analysis but varied depending on the gene region targeted and the barcoding system used. A relative abundance of 0.25% was identified as a threshold below which the analysis of spurious taxa can be prevented to a large extent. Most spurious taxa (approx. 70%) detected in simplified communities occurred in samples multiplexed in the same sequencing run and were present in only one of ten runs. Use of the 0.25% relative abundance threshold decreased the coefficient of variations calculated on richness in the same six human fecal samples across seven sequencing runs by 38% compared with singleton filtering. The output of beta -diversity analyses of human fecal communities was markedly affected by both the filtering strategy and the type of phylogenetic distances used for comparing samples. Importantly, major findings were confirmed by using data generated in a second sequencing facility. Conclusions: Handling of artifact sequences during bioinformatic processing of 16S rRNA gene amplicon data requires careful attention to avoid the generation of misleading findings. A threshold of relative abundance of 0.25% is more appropriate than singleton removal, although study-specific analysis strategies are mandatory. We propose the concept of effective richness, which will help comparing results across studies.

Identification of 16S rRNA mutations in Mycoplasma genitalium potentially associated with tetracycline resistance in vivo but not selected in vitro in M. genitalium and Chlamydia trachomatis

2021 ◽  
Author(s):  
Chloé Le Roy ◽  
Arabella Touati ◽  
Carla Balcon ◽  
Justine Garraud ◽  
Jean-Michel Molina ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Tetracycline Resistance ◽  
Mycoplasma Genitalium ◽  
Rrna Gene ◽  
Resistant Mutants ◽  
The 16S Rrna Gene

Abstract Objectives Tetracyclines are widely used for the treatment of bacterial sexually transmitted infections (STIs) and recently have been used successfully for post-exposure prophylaxis of STIs in MSM. We investigated the in vitro and in vivo development of tetracycline resistance in Chlamydia trachomatis and Mycoplasma genitalium and evaluated 16S rRNA mutations associated with acquired resistance in other bacteria. Methods In vitro selection of resistant mutants of reference strains of C. trachomatis and M. genitalium was undertaken by serial passage in medium containing subinhibitory concentrations of tetracycline or doxycycline, respectively. The 16S rRNA gene of the two microorganisms was amplified and sequenced at different passages, as were those of 43 C. trachomatis- and 106 M. genitalium-positive specimens collected in France from 2013 to 2019. Results No tetracycline- or doxycycline-resistant strains of C. trachomatis and M. genitalium, respectively, were obtained after 30 serial passages. The tetracycline and doxycycline MICs were unchanged and analysis of the 16S rRNA gene, the molecular target of tetracyclines, of C. trachomatis and M. genitalium revealed no mutation. No mutation in the 16S rRNA gene was detected in C. trachomatis-positive specimens. However, six M. genitalium-positive specimens harboured a mutation potentially associated with tetracycline resistance without known prior tetracycline treatment for patients. Conclusions Tetracyclines did not select in vitro-resistant mutants of C. trachomatis or M. genitalium. However, 16S rRNA mutations either responsible for or associated with tetracycline resistance in other bacteria, including mycoplasma species, were identified in several M. genitalium-positive specimens.

scholarly journals ‘Candidatus Burkholderia calva’ and ‘Candidatus Burkholderia nigropunctata’ as leaf gall endosymbionts of African Psychotria

2004 ◽  
Vol 54 (6) ◽  
pp. 2237-2239 ◽  
Author(s):  
Sandra Van Oevelen ◽  
Rupert De Wachter ◽  
Peter Vandamme ◽  
Elmar Robbrecht ◽  
Els Prinsen
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Novel Species ◽  
Gene Analysis ◽  
Rrna Gene ◽  
16S Rrna Gene Analysis ◽  
Culture Collections ◽  
Type Strains

Phylogenetic 16S rRNA gene analysis was used to assign the bacterial leaf-nodulating endosymbionts of two tropical African Psychotria species to the genus Burkholderia. The microsymbionts of the different Psychotria hosts were recognized as distinct and novel species of Burkholderia on the basis of relatively low intersequence similarities and sufficiently large evolutionary distances when compared with each other and their closest validly named neighbours. The obligate endosymbiotic nature of the bacteria prevented their in vitro cultivation and the deposition of type strains to culture collections. Therefore, the provisional status Candidatus is assigned to the bacterial partners of Psychotria calva and Psychotria nigropunctata, with the proposal of the names ‘Candidatus Burkholderia calva’ and ‘Candidatus Burkholderia nigropunctata’, respectively.

In vitro analysis of the pea chloroplast 16S rRNA gene promoter

1989 ◽  
Vol 9 (12) ◽  
pp. 5650-5659
Author(s):  
E Sun ◽  
B W Wu ◽  
K K Tewari
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Topoisomerase I ◽  
Transcriptional Start Site ◽  
Gene Promoter ◽  
In Vitro Transcription ◽  
Rrna Gene ◽  
Start Site

A cloned pea chloroplast 16S rRNA gene promoter has been characterized in detail by use of a homologous in vitro transcription system that contains a highly purified chloroplast RNA polymerase. The in vivo and in vitro 16S rRNA transcriptional start site has been identified to be a T on the plus strand, 158 bases upstream of the mature 5' end of the gene. BAL 31 deletions of the 16S rRNA leader region demonstrated that the bases between -66 to +30 relative to the transcriptional start site (+1) are necessary for specific 16S transcription. Disruption of canonical TTGACA or TATAAT elements within this region caused complete transcriptional inactivation and prevented protein binding. The topological requirement for 16S transcription was examined by using a construct that synthesized a transcript from the 16S promoter and released it from a pea plastid putative terminator sequence. This minigene was relaxed in vitro with a topoisomerase I from pea chloroplast. It was shown that the 16S promoter was most active when the minigene plasmid was supercoiled.

scholarly journals Isolation of probiotics bacterium from coral reef for controlling vibriosis in tiger shrimp (Penaeus monodon) larvae

2013 ◽  
Vol 9 (2) ◽  
pp. 168
Author(s):  
Ade Dwi Sasanti ◽  
. Widanarni ◽  
. Sukenda
Keyword(s):  
Growth Rate ◽  
Coral Reef ◽  
Vibrio Harveyi ◽  
Larval Mortality ◽  
Positive Control ◽  
Shrimp Culture ◽  
Tiger Shrimp ◽  
Pathogenic Vibrio

<p>Pathogenic Vibrio, especially luminous Vibrio harveyi, could cause mass mortality in tiger shrimp culture. One of the technique to work against luminous Vibrio is, using probiotic bacteria to inhibit the luminous Vibrio growth. This study was carried out to obtain bacteria isolates from coral reef which potentially inhibit V. harveyi growth. A total of 110 isolates were isolated from Acropora sp, Merulina sp, Hystrix sp., Poecillophora sp, Porites sp and Haliophora sp., and have probiotic activity against V. harveyi in in vitro and in vivo test.Of the total 110 isolates, 54 isolates show the inhibiting zone. Two isolates(8A and 1C)were not pathogenic and have the most effective activity in inhibiting growth of V. harveyi and significantly reduced larval mortality in in vitro and in vivo test. Treatment using probiotics candidate have significant different survival rate (83.33%) compared with positive control (61.67%). The growth rate of lenght of larvae treatment with isolate of 8A (5.25%) and 1C (5.06%) show the significant different compared with positive control (3.54%). The growth rate of weight of larvae treatment withisolate of 8A (17.51%) and 1C (17.61%) show significant different compared with negative (15.27%) and positive control (14.69%).<br /><br />Key word: coral reef, probiotic, tiger shrimp, vibriosis, V. harveyi.</p><p> </p><p><strong>ABSTRAK</strong><br /><br />Vibrio patogen, khususnya Vibrio harveyi berpendar, dapat menyebabkan kematian massal pada budidaya udang windu. Salah satu alternatif untuk menghambat Vibrio harveyi berpendar adalah dengan menggunakan bakteri probiotik yang dapat menekan pertumbuhan Vibrio tersebut. Penelitian ini bertujuan untuk mendapatkan isolat bakteri dari terumbu karang yang potensial menghambat pertumbuhan V. harveyi. Total 110 isolat diisolasi dari Acropora sp, Merulina sp., Hystrix sp., Poecillophora sp., Porites sp. dan Haliophora sp, dilakukan penapisan untuk melihat aktivitas kemampuannya melawan V. harveyi MR 5339 RfR dalam uji in vitro dan uji in vivo. Sebanyak 54 isolat teridentifikasi mampu menghasilkan zona hambat. Dua isolat (8A dan 1C) terbukti tidak bersifat patogen dan memiliki aktivitas probiotik melawan V. harveyi MR 5339 RfR pada uji in vitro dan in vivo. Tingkat kelangsungan hidup larva pada perlakuan yang diberi kandidat probiotik dari kedua isolat tersebut adalah 83,33%, dan menunjukkan hasil yang berbeda nyata dengan kontrol positif (61,67%). Laju pertumbuhan panjang larva yang diberi isolat 8A (5,25%) dan 1C (5,06%)menunjukkan hasil yang berbeda nyatajika dibandingkan dengan kontrolpositif (3,54%). Laju pertumbuhan bobot yang diberi isolat 8A (17,51%) dan 1C (17,61%) menunjukkan hasil yang berbeda nyata terhadap kontrol negative (15,27%) dan kontrol positif (14,69%).<br /><br />Kata kunci: probiotik, terumbu karang,udang windu, V. harveyi, vibriosis.<br /></p>

scholarly journals Microbiome of Odontogenic Abscesses

2021 ◽  
Vol 9 (6) ◽  
pp. 1307
Author(s):  
Sebastian Böttger ◽  
Silke Zechel-Gran ◽  
Daniel Schmermund ◽  
Philipp Streckbein ◽  
Jan-Falco Wilbrand ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Oral Microbiome ◽  
Minor Role ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Bacterial Strains ◽  
16S Rrna Gene Analysis ◽  
Odontogenic Infections ◽  
Odontogenic Abscess

Severe odontogenic abscesses are regularly caused by bacteria of the physiological oral microbiome. However, the culture of these bacteria is often prone to errors and sometimes does not result in any bacterial growth. Furthermore, various authors found completely different bacterial spectra in odontogenic abscesses. Experimental 16S rRNA gene next-generation sequencing analysis was used to identify the microbiome of the saliva and the pus in patients with a severe odontogenic infection. The microbiome of the saliva and the pus was determined for 50 patients with a severe odontogenic abscess. Perimandibular and submandibular abscesses were the most commonly observed diseases at 15 (30%) patients each. Polymicrobial infections were observed in 48 (96%) cases, while the picture of a mono-infection only occurred twice (4%). On average, 31.44 (±12.09) bacterial genera were detected in the pus and 41.32 (±9.00) in the saliva. In most cases, a predominantly anaerobic bacterial spectrum was found in the pus, while saliva showed a similar oral microbiome to healthy individuals. In the majority of cases, odontogenic infections are polymicrobial. Our results indicate that these are mainly caused by anaerobic bacterial strains and that aerobic and facultative anaerobe bacteria seem to play a more minor role than previously described by other authors. The 16S rRNA gene analysis detects significantly more bacteria than conventional methods and molecular methods should therefore become a part of routine diagnostics in medical microbiology.

scholarly journals The growth response of rice (Oryza sativa L. var. FARO 44) in vitro after inoculation with bacterial isolates from a typical ferruginous ultisol

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Musa Saheed Ibrahim ◽  
Beckley Ikhajiagbe
Keyword(s):  
16S Rrna ◽  
Bacillus Cereus ◽  
Proteus Mirabilis ◽  
Growth Response ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Rice Seedlings ◽  
Rrna Gene Sequencing

Abstract Background Rice forms a significant portion of food consumed in most household worldwide. Rice production has been hampered by soil factors such as ferruginousity which has limited phosphorus availability; an important mineral component for the growth and yield of rice. The presence of phosphate-solubilizing bacteria (PSB) in soils has been reported to enhance phosphate availability. In view of this, the present study employed three bacteria species (BCAC2, EMBF2 and BCAF1) that were previously isolated and proved P solubilization capacities as inocula to investigate the growth response of rice germinants in an in vitro setup. The bacteria isolates were first identified using 16S rRNA gene sequencing and then applied as inoculum. The inolula were prepared in three concentrations (10, 7.5 and 5.0 ml) following McFarland standard. Viable rice (var. FARO 44) seeds were sown in petri dishes and then inoculated with the three inocula at the different concentrations. The setup was studied for 28 days. Results 16S rRNA gene sequencing identified the isolates as: isolate BCAC2= Bacillus cereus strain GGBSU-1, isolate BCAF1= Proteus mirabilis strain TL14-1 and isolate EMBF2= Klebsiella variicola strain AUH-KAM-9. Significant improvement in rice germination, morphology, physiology and biomass parameters in the bacteria-inoculated setups was observed compared to the control. Germination percentage after 4 days was 100 % in the inoculated rice germinants compared to 65% in the control (NiS). Similarly, inoculation with the test isolates enhanced water-use efficiency by over 40%. The rice seedlings inoculated with Bacillus cereus strain GGBSU-1 (BiS) showed no signs of chlorosis and necrosis throughout the study period as against those inoculated with Proteus mirabilis strain TL14-1 (PiS) and Klebsiella variicola strain AUH-KAM-9 (KiS). Significant increase in chlorophyll-a, chlorophyll-b and alpha amylase was observed in the rice seedlings inoculated with BiS as against the NiS. Conclusion Inoculating rice seeds with Bacillus cereus strain GGBSU-1, Proteus mirabilis strain TL14-1 and Klebsiella variicola strain AUH-KAM-9 in an in vitro media significantly improved growth parameters of the test plant. Bacillus cereus strain GGBSU-1 showed higher efficiency due to a more improved growth properties observed.

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