Filamentous microorganisms are main producers of organic acids, enzymes, and pharmaceutical agents such as antibiotics and other active pharmaceutical ingredients. With their complex cell morphology, ranging from dispersed mycelia to dense pellets, the cultivation is challenging. In recent years, various techniques for tailor‐made cell morphologies of filamentous microorganisms have been developed to increase product formation and have been summarised under the term morphology engineering. These techniques, namely microparticle‐enhanced cultivation, macroparticle‐enhanced cultivation, and alteration of the osmolality of the culture medium by addition of inorganic salts, the salt‐enhanced cultivation, are presented and discussed in this review. These techniques have already proven to be useful and now await further proof‐of‐concept. Furthermore, the mechanical behaviour of individual pellets is of special interest for a general understanding of pellet mechanics and the productivity of biotechnological processes with filamentous microorganisms. Correlating them with substrate uptake and finally with productivity would be a breakthrough not to be underestimated for the comprehensive characterisation of filamentous systems. So far, this research field is under‐represented. First results on filamentous pellet mechanics are discussed and important future aspects, which the filamentous expert community should deal with, will be presented and critically discussed.

中文翻译：

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通过形态工程技术和丝状颗粒系统机械诱导应力影响细胞形态的挑战——批判性评论

丝状微生物是有机酸、酶和药剂（例如抗生素和其他活性药物成分）的主要生产者。由于其细胞形态复杂，从分散的菌丝体到致密的颗粒，培养具有挑战性。近年来，已经开发了各种定制丝状微生物细胞形态的技术来增加产物的形成，并已被概括为形态工程这一术语。本综述介绍并讨论了这些技术，即微粒强化培养、大粒子强化培养以及通过添加无机盐改变培养基的渗透压（盐强化培养）。这些技术已经被证明是有用的，现在等待进一步的概念验证。此外，单个颗粒的机械行为对于总体了解颗粒力学和丝状微生物生物技术过程的生产力特别有意义。将它们与底物吸收以及最终与生产力联系起来对于丝状系统的综合表征来说将是一个不可低估的突破。到目前为止，这一研究领域的代表性不足。讨论了丝状颗粒力学的初步结果，并将提出并批判性地讨论丝状专家界应该处理的未来重要方面。