The present study describes a direct shoot regeneration-based micropropagation procedure for Vanilla planifolia. Two types of explant (i.e. shoot apex and stem nodal segment) were screened for their shoot induction po...The present study describes a direct shoot regeneration-based micropropagation procedure for Vanilla planifolia. Two types of explant (i.e. shoot apex and stem nodal segment) were screened for their shoot induction potential following a three-month treatment with 6-benzylaminopurine (BAP) and α-Naphthaleneacetic acid (NAA). Results indicated that the shoot apices were poor candidates for shoot induction whereas the stem nodal segments showed potential for shoot initiation at a rate of up to 6 shoots/explant. Stem nodal segments were the most responsive as shoots formed (55 shoots) directly following treatments with 1 mg/L BAP at half strength MS medium after the third subculture. In addition, more shoots were produced on solid medium treatments compared to the liquid medium treatments in two strengths of mediums tested. Regenerated plantlets derived from the 1 mg/L of BAP treatment were induced to root following a one month culture in growth regulator-free MS medium. There was 90% survival rate of the rooted plantlets after acclimatization in the greenhouse. The findings in the present study would be helpful for large-scale mass propagation of Vanilla planifolia using this simple and efficient protocol.展开更多
Large quantities of <em>Rhizobium leguminosarum</em> by conventional technique are a time-consuming and labor-intensive method of production. The selection of different types of nutrient media for the prod...Large quantities of <em>Rhizobium leguminosarum</em> by conventional technique are a time-consuming and labor-intensive method of production. The selection of different types of nutrient media for the production of large amounts of rhizobium at low cost, determination of environmental regulators of culture medium and the effect of different levels of air flow into nutrition media have been investigated. <em>Rhizobium</em> cultured in modified air lift bioreactor as improved conventional system using Yeast Extract Mannitol Broth by assessing aeration and agitation in their submerged growth. For selection of suitable nutrient media for <em>Rhizobium </em>before mass production, YMA (Yeast Mannitol Agar), YSA (Yeast Sucrose Agar), YMA + bromthymol blue (BTB), YMA + Congo red (CR) medium was tested. To optimize the growing conditions of different temperatures, pH levels and salt strengths were investigated. Three air flow speeds at the rate of 0.01, 0.05 and 0.1 VVM for oxygen supply were ensured. A thick off-white bacterial colony was observed on the YMA plate among different culture media. Room temperature (25<span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span>C - 30<span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span>C), neutral pH (7.0), low salinity (1%) was observed to be suitable among the environmental conditions for <em>Rhizobium</em> mass production. The maximum density of <em>Rhizobium</em> was observed using air supply of 0.1 VVM level in bioreactor system. The result seemed that the air supply and agitation was an important growth factor in submerged cultivation. This study provides useful information on large scale production of <em>Rhizobium</em> of interest employing low cost effective modified air lift bioreactor within less time.展开更多
文摘The present study describes a direct shoot regeneration-based micropropagation procedure for Vanilla planifolia. Two types of explant (i.e. shoot apex and stem nodal segment) were screened for their shoot induction potential following a three-month treatment with 6-benzylaminopurine (BAP) and α-Naphthaleneacetic acid (NAA). Results indicated that the shoot apices were poor candidates for shoot induction whereas the stem nodal segments showed potential for shoot initiation at a rate of up to 6 shoots/explant. Stem nodal segments were the most responsive as shoots formed (55 shoots) directly following treatments with 1 mg/L BAP at half strength MS medium after the third subculture. In addition, more shoots were produced on solid medium treatments compared to the liquid medium treatments in two strengths of mediums tested. Regenerated plantlets derived from the 1 mg/L of BAP treatment were induced to root following a one month culture in growth regulator-free MS medium. There was 90% survival rate of the rooted plantlets after acclimatization in the greenhouse. The findings in the present study would be helpful for large-scale mass propagation of Vanilla planifolia using this simple and efficient protocol.
文摘Large quantities of <em>Rhizobium leguminosarum</em> by conventional technique are a time-consuming and labor-intensive method of production. The selection of different types of nutrient media for the production of large amounts of rhizobium at low cost, determination of environmental regulators of culture medium and the effect of different levels of air flow into nutrition media have been investigated. <em>Rhizobium</em> cultured in modified air lift bioreactor as improved conventional system using Yeast Extract Mannitol Broth by assessing aeration and agitation in their submerged growth. For selection of suitable nutrient media for <em>Rhizobium </em>before mass production, YMA (Yeast Mannitol Agar), YSA (Yeast Sucrose Agar), YMA + bromthymol blue (BTB), YMA + Congo red (CR) medium was tested. To optimize the growing conditions of different temperatures, pH levels and salt strengths were investigated. Three air flow speeds at the rate of 0.01, 0.05 and 0.1 VVM for oxygen supply were ensured. A thick off-white bacterial colony was observed on the YMA plate among different culture media. Room temperature (25<span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span>C - 30<span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span>C), neutral pH (7.0), low salinity (1%) was observed to be suitable among the environmental conditions for <em>Rhizobium</em> mass production. The maximum density of <em>Rhizobium</em> was observed using air supply of 0.1 VVM level in bioreactor system. The result seemed that the air supply and agitation was an important growth factor in submerged cultivation. This study provides useful information on large scale production of <em>Rhizobium</em> of interest employing low cost effective modified air lift bioreactor within less time.
