Institute of Technical Chemistry, Leibniz University of Hannover, Callinstr. 5, 30167 Hannover, Germany.
Molecules. 2019 Sep 15;24(18):3356. doi: 10.3390/molecules24183356.
The sesquiterpene (+)-zizaene is the direct precursor of khusimol, the main fragrant compound of the vetiver essential oil from and used in nearly 20% of men's fine perfumery. The biotechnological production of such fragrant sesquiterpenes is a promising alternative towards sustainability; nevertheless, product recovery from fermentation is one of the main constraints. In an effort to improve the (+)-zizaene recovery from a metabolically-engineered , we developed an integrated bioprocess by coupling fermentation and (+)-zizaene recovery using adsorber extractants. Initially, (+)-zizaene volatilization was confirmed from cultivations with no extractants but application of liquid-liquid phase partitioning cultivation (LLPPC) improved (+)-zizaene recovery nearly 4-fold. Furthermore, solid-liquid phase partitioning cultivation (SLPPC) was evaluated by screening polymeric adsorbers, where Diaion HP20 reached the highest recovery. Bioprocess was scaled up to 2 L bioreactors and in situ recovery configurations integrated to fermentation were evaluated. External recovery configuration was performed with an expanded bed adsorption column and improved (+)-zizaene titers 2.5-fold higher than LLPPC. Moreover, internal recovery configuration (IRC) further enhanced the (+)-zizaene titers 2.2-fold, whereas adsorption velocity was determined as critical parameter for recovery efficiency. Consequently, IRC improved the (+)-zizaene titer 8.4-fold and productivity 3-fold from our last report, achieving a (+)-zizaene titer of 211.13 mg L and productivity of 3.2 mg L h. This study provides further knowledge for integration of terpene bioprocesses by in situ product recovery, which could be applied for many terpene studies towards the industrialization of fragrant molecules.
倍半萜（+）-姜黄烯是库希醇的直接前体，库希醇是来自 的香根草精油的主要芳香化合物，用于近 20%的男士优质香水。利用生物技术生产这种芳香倍半萜是实现可持续性的有前途的替代方法；然而，从发酵中回收产品是主要限制之一。为了提高代谢工程化 中（+）-姜黄烯的回收率，我们通过使用吸附剂萃取剂将发酵和（+）-姜黄烯回收耦合，开发了一种集成的生物工艺。最初，从没有萃取剂的培养物中证实了（+）-姜黄烯的挥发，但应用液-液相间分配培养（LLPPC）可使（+）-姜黄烯的回收率提高近 4 倍。此外，通过筛选聚合物吸附剂评估了固-液相间分配培养（SLPPC），其中 Diaion HP20 达到了最高的回收率。生物工艺扩大到 2 L 生物反应器，并评估了集成到发酵中的原位回收配置。外部回收配置是使用扩展床吸附柱进行的，与 LLPPC 相比，（+）-姜黄烯的滴度提高了 2.5 倍。此外，内部回收配置（IRC）进一步将（+）-姜黄烯的滴度提高了 2.2 倍，而吸附速度被确定为回收效率的关键参数。因此，IRC 将（+）-姜黄烯的滴度提高了 8.4 倍，比我们的上一份报告提高了 3 倍，达到了 211.13 mg L 的（+）-姜黄烯滴度和 3.2 mg L h 的生产率。本研究为通过原位产物回收集成萜类生物工艺提供了进一步的知识，这可应用于许多萜类研究，以实现芳香分子的工业化。
